Kingsnakes versus Rattlesnakes

Kingsnakes eat rattlesnakes, hence their name. Apparently kingsnakes are either immune to or tolerant of rattlesnake venom. Kingsnakes also eat other snakes, lizards, amphibians, birds and bird eggs, and rodents.

Rattlesnakes can identify kingsnakes by smell. Rattlesnakes usually retreat in presence of a kingsnake and hold their head and tail close to the ground while arching their back and attempt to hit the kingsnake. Watch a 3-minute Discovery Channel video of a common kingsnake attacking and eating a rattlesnake:


Kingsnakes are usually docile, but when disturbed, they may hiss, vibrate their tail, and strike. If seized by a predator such as a coyote, the kingsnake can expel a noxious musk.

Kingsnakes come in a great variety of patterns and colors. There is some controversy over names and how many varieties there are. This is made more confusing because some varieties can interbreed with other varieties. I use the Arizona-Sonora Desert Museum naming convention here. Most kingsnake adults are three to six feet long. Below are photos of the most common varieties in the southwest. All kingsnakes have smooth scales unlike the ridged scales of the gopher snake. All kingsnakes are powerful constrictors.

Desert Kingsnake

Kingsnake desert

This black and white (or cream) is the most common kingsnake in the Tucson area. It is native to Arizona, New Mexico, and Texas. It normally grows to four feet but some are over six feet long. This kingsnake normally mates from March through June and produces up to 12 eggs that incubate for 60 days. Hatchlings are 8- to 10 inches long.

Common Kingsnake

Kingsnake common

The common kingsnake used to be called the California kingsnake. It has alternating brown/black and white/cream to yellow colored bands. Adults range from 2.5 to 6 feet long. This snake occurs throughout most of Arizona, California, and Baja California. Normal mating time is May through August. The females produce as many as 24 eggs which hatch in 60 days. Hatchlings are 6- to 8 inches long and are more brightly colored than the parents.

Sonoran Kingsnake

Kingsnake Sonoran

The Sonoran kingsnake is usually deep chocolate brown which may look black in some lighting conditions. It occurs in southern Arizona and in Mexico south to Sinaloa. Young snakes may have spots of white or yellow under their chin. This snake is commonly 3- to 4 feet long and rather plump compared to other kingsnakes.

Mountain Kingsnake

Kingsnake Arizona Mtn

This pretty snake is variously called the Arizona Mountain kingsnake or Sonoran Mountain kingsnake, It may be 2.5 to 4 feet long. This snake inhabits the Sierra Madre in Sonora and several mountain ranges in southern Arizona. I have seen this snake in the Bradshaw Mountains near Jerome. Some occur also in Utah and Nevada. It may be confused with the coral snake, but it is much larger. Remember the rhyme: “Red touch black, OK Jack.” These snakes breed in spring and generally produce four to nine eggs.

Milk snake

Kingsnake Sinaloan Milksnake

On this snake, the red bands are much wider than the black and white/yellow bands. It, too, can be confused with the coral snake. The rest of the rhyme: “Red touch yellow, kill a fellow.” In kingsnakes, the red band is surrounded by black bands.

The milk snake is commonly 1.5- to 4.5 feet long. It occurs mainly in southern Sonora, but there have been some specimens collected near the Little Colorado River in northern Arizona. This snake occurs mainly in forests and is mainly nocturnal. Breeding is similar to the mountain kingsnake.

I handle snakes at the Arizona-Sonora Desert Museum including all the kingsnakes shown above. Kingsnakes are my favorite snake. They seem more curious than other snakes. When I’m holding a snake and someone comes near, the kingsnake will take a look and flick its tongue to get a taste. Taste, by the way, is the snake’s most important sense. Their forked tongue picks up particles in the air which are analyzed by the Jacobson’s organ in the roof of the mouth. The organ is so sensitive that it can distinguish differences from each side of the forked tongue. This gives the snake a sense of direction for where the taste is coming from.

Kingsnakes have many pointy teeth to grip their prey. In the photo below, notice that snakes have four rows of teeth on top. Notice also that the teeth are very small. I have never been bitten, but other Docents have been. They say it is no big deal because the teeth are so small.

 Snake teeth

Besides the western kingsnakes described above, several species, mainly black varieties, live in the mid-western and eastern states. The eastern kingsnakes eat copperheads as well as rattlesnakes.

Be kind to kingsnakes you find in your yard. They will help protect you from rattlesnakes and eat rodents.

See also:

Gopher snakes
Clever Horned Lizard
Metachromatic spiny lizards
Speckled Rattlesnakes
Venomous Lizards (Gila monster, Beaded lizard)

Gopher Snakes

Gopher snakes are large, heavy-bodied snakes that often pretend to be rattlesnakes. They are commonly four to five feet long but can get to over nine feet long. Gopher snakes are non-venomous and good to have around because they eat rodents.

At the Arizona-Sonora Desert Museum, keepers removed one gopher snake from the prairie dog enclosure that measured nine feet, two inches long. Guess what it was eating.

Gopher snakes vary in color but are usually yellowish, cream-colored, or tan with many black, brown or reddish blotches on their backs. Check out the top photo here to see the full length pattern. Pretty isn’t it. The scales on their back are ridged rather than smooth.

When disturbed, gopher snakes will hiss, flatten their heads, and vibrate their tails. Because of this behavior and their color pattern, they are often mistaken for rattlesnakes. As you can note from the photos below, gopher snakes have round-pupils whereas rattlesnakes have slit pupils like cat’s eyes.

Gopher Snake


Speckled rattlesnake


All you have to do is get close enough to look them in the eye to tell the difference.

Gopher snakes have a large range: all of the U.S., southern Canada, and as far south as southern Sinaloa in Mexico. These snakes can be found in deserts, prairies, woodlands, brushlands, (and in my yard), from sea level to over 9,000 feet. They are called bull snakes or pine snakes in some parts of the country.

Gopher snakes are non-venomous constrictors. They hunt during the day except in very hot weather, when they become night hunters. Their prey includes rodents, young rabbits, lizards, birds, bird eggs, other snakes, and yes, gophers. They hunt mainly by sense of smell. Gopher snakes are good climbers and can even climb a large saguaro cactus to check out what might be inhabiting those holes made by woodpeckers. Apparently their tough scales protect them from the spines.

According to the Arizona-Sonora Desert Museum, “Male gopher snakes engage in ritualistic combats during the spring mating season. The combatants remain on the ground, entwined from tail to neck. Each tries to maintain its head and body position, although occasionally they will exert so much force that they roll. Hissing frequently, they rarely bite one another. Presumably the combat ritual is a means of determining the sexual fitness of a male, for usually only the victor will copulate afterwards.” I understand that this combat is performed when a female is nearby.

I have seen similar behavior with rattlesnakes, but instead of remaining on the ground, the ones I saw were intertwined vertically for almost half their length.

The female will lay up to 24 eggs, in the summer, which hatch in the fall.

Gopher snakes use communal dens for winter hibernation.

If you see a gopher snake in your yard, let it be. It may do you the service of eating your pack rats, then move on.

A version of this article first appeared in the Arizona Daily Independent.

See also:

Clever Horned Lizard

Metachromatic spiny lizards


Speckled Rattlesnakes

Venomous Lizards

The most dangerous venomous animals of the Southwest

Speckled-rattlesnakeThe southwestern desert has a reputation for venomous critters, but which are most dangerous? I attended a lecture at the Arizona-Sonora Desert Museum given by James W. Cornett, a biologist, author, and emeritus Curator of Natural Science at the Palm Springs Desert Museum. Cornett has studied venomous animals for over 30 years and gave us a list of what he considers the thirteen most dangerous animals.

This list is subjective and includes consideration of the toxicity of the venom, the amount of venom injected, the possibility of an allergic reaction, the abundance of the animal, and the probability you could actually encounter the animal. Here is his list from the least dangerous to most dangerous:

13. Tarantulas. The venom is generally not dangerous to humans and it takes much provocation to get a tarantula to bite you.

12. Centipedes. Some of these can get over 10 inches long (but most are about 5 – to 8 inches) They deliver venom by pinching with its front legs. One death has been attributed to a centipede bite.

11. Velvet ants (actually wasps). These look fuzzy and cute but deliver a very painful bite.

10. Gila monster. These lizards are venomous but it takes some provocation to get them to bite you. (Note: that provocation can be trying to be nice and carrying one off the road so that it doesn’t get run over.)

9. Coral snakes. The coral snakes in the Southwest are generally small. More deaths occur in the East where the snakes are larger.

8. Cone-nosed bugs (aka Kissing bugs). Bites from these bugs can produce an allergic reaction and can transmit Chagas Disease, a chronic and debilitating protozoan infection. Cone-nosed bugs feed on the blood of other animals, mostly rodents.

7. Ants. Swarming ants, by their large numbers can deliver painful bites and cause allergic reactions.

6. Scorpions. Most scorpion stings in the southwest are not dangerous. However, bark scorpion venom is dangerous to humans.

5. Brown (recluse) spiders. The venom is very persistent and causes tissue damage.

4. Wasps.

3. Black Widow spiders. Drop for drop, black widow venom is the most toxic of any animal in the southwest. And now, we are seeing more Brown Widow spiders coming into the area.

2. Rattlesnakes. This venom does great tissue damage and two species, the Tiger rattlesnake and Mohave rattlesnake also have neurotoxic venom. By the way, there are 18 rattlesnake species common to Arizona.

And the most dangerous venomous animal:

1. Africanized Honey Bees. According to Cornett, bees cause more deaths than all the other animals combined.

Besides these animals, Cornett mentioned some snakes that are considered only mildly venomous, some of which are commonly kept as pets. None of these snakes have fangs, but the do have enlarged back teeth and toxic saliva. They need to chew on you for a while to work the venom in. These snakes include the ring-necked snake, black-headed snake, spotted night snake, lyre snake, hog-nosed snake, and the common garter snake.

Cornett related an incident with a hog-nosed snake. This snake was in an exhibit at the Palm Springs Desert Museum. Cornett was attempting to feed it a mouse, but since he handled the mouse, its scent got on Cornett’s hand. The snake bit him on the web between thumb and forefinger and chewed for a while before it could be detached. This mild venom caused swelling and discoloration of Cornett’s hand and arm and produced blisters for about a month. Nobody has antivenom for these snakes.

For more information on venomous animals, see:

Desert Bees and Africanized Bees

Scorpions, Vinegaroons, and Sun Spiders

Tarantula Hawks Deliver The Big Sting

Venomous Centipedes and Cyanide-Oozing Millipedes

Who’s Afraid of Tarantulas?


Venomous Lizards

Speckled Rattlesnakes at ASDM

The Arizona-Sonora Desert Museum has a new exhibit on Speckled rattlesnakes. The exhibit will run through November.


Speckled rattlesnakes most commonly inhabit dry, rocky, granite-filled canyons and their speckles resemble rock pattern and color, giving the snakes camouflage. Speckled rattlesnakes come in several colors including white, orange, pink, blue, tan, silver, black, and gray. They are generally small, 2- to 3 feet, but one subspecies can be up to 5 feet long.

Their range includes Central and Western Arizona, Southeast California, Northwest Sonora, Baja California, and several islands in the Gulf of California.

The exhibit focuses on the characteristics of skin color and pattern.

For more information on rattlesnakes in general see my article:RATTLESNAKES.


There are 17 species or subspecies of rattlesnakes in Arizona and they all object to being stepped on. So watch where you walk. In my field experience as a geologist, I’ve encountered many rattlesnakes (26 on one morning), and most of the time they don’t rattle. They prefer to remain inconspicuous. See here for a list of all recognized rattlesnake species and subspecies.


Some herpetologists regard rattlesnakes as one of the most highly specialized animals on the planet. The venom, a toxic saliva, is a complex mixture of enzymes that include hemotoxins, that attack the blood and start the digestion process in tissue, and anticoagulants. The Mohave rattlesnake also carries neurotoxic venom that may cause circulatory arrest or respiratory paralysis. That said, however, fewer than 1% of people bitten in the U.S. die as a result of the bite, but many sustain tissue damage. About 20% of defensive bites are dry – no venom injected. Venom is injected via curved fangs which fold back into the snake’s mouth. Rattlesnakes seem to have spare parts to replace damaged fangs. Baby rattlesnakes are venomous and ready to go, they just can’t inject as much venom as a larger snake.

If you are bitten, the University of Arizona College of Pharmacy recommends that you get to a hospital to get antivenom and treatment for tissue damage. Don’t bring the snake; the antivenom treats all bites. Also don’t use tourniquets, that just concentrates the venom and produces more tissue damage. Don’t use ice for the same reason. Don’t cut and suck; you can’t get enough venom out to make a difference, and, if a friend does it for you, he takes a chance of envenomating himself. Do remove tight clothing, shoes, jewelry from the affected limb.

Rattlesnakes are pit vipers, which means they have heat-sensing organs located between their eyes and nose. A rattlesnake can detect the heat of a candle at 30 feet. Some researchers claim that a rattlesnake can perceive a temperature difference of as little as 0.01 degree Fahrenheit at one foot. The snakes use this heat-sensing ability in several ways. They can follow the heat trail of prey even in total darkness. They can tell if an animal is too large to be prey and thereby avoid it. And, the exothermic (cold-blooded) snake can use their temperature sensor to help find places to properly regulate body temperature.

Rattlesnakes are most active in the warmer times of year, but in Arizona, they may be out and about any time the temperature is between 70 and 90 degrees F.

Rattlesnakes are born live, rather than hatch from eggs. The babies have the first segment of the rattle, but can’t make a noise until it sheds and gets another bead on its rattle. Mother rattlesnakes care for their young at least until after the first shed. It is a myth that you can tell the age of a snake by counting the beads on the rattle. Beads are added at each shed, and the snake may shed several times a year. The rattle material is keratin, the same as your fingernails. There isn’t anything inside the rattles; the noise comes from the segments bumping against each other as the snake vibrates its tail up to 60 times per second.

Rattlesnake eyes have slit pupils like cat eyes. The gopher snake, a non-venomous constrictor, is often mistaken for a rattlesnake, but it has round pupils and lacks the triangular head of the rattlesnake.

Other snake myths. Snakes cannot dislocate their jaws. They can open their mouths very wide because they have two jaw joints on each side separated by a (quadrate) bone. Snakes also lack bony chins. Each half of the lower jaw is separated by cartilage which enables the snake to move the lower jaws independently.

Rodents are the main prey of the rattlesnake, so the snakes provide a valuable service. They also take birds, lizards, and baby rabbits and squirrels.

At the Arizona-Sonora Desert Museum, the staff capture an average of 100 rattlesnakes per year on the grounds. After capture, the snakes are marked by color-coding the tails and, more recently, by inserting a radio chip to allow tracking. The snakes are released on the far reaches of the grounds. Rattlesnakes, however, are very territorial, so many return. So, if you are at the Museum and see a rattlesnake with a multi-colored tail, you will know that particular snake is a return visitor. And no human visitors have ever been bitten by a rattlesnake at the Museum.