MO Missouri Porch

Wildlife & Encounters

Snakes — the five venomous ones, and why you shouldn't kill any of them

The plain answer: Missouri has about 47 kinds of snake, and only five are venomous. Bites are rare, deaths rarer — and every native snake here is protected, so it's generally against the law to kill one. Learn the five, learn to look from a distance, and you're set.

The five venomous snakes

All five are pit vipers

Missouri has no coralsnake and no western diamondback. These are the only five venomous snakes in the state:

Copperhead

The most common, and the one behind most bites — but its bite is rarely life-threatening. Tan with dark hourglass bands; found statewide.

Cottonmouth (water moccasin)

Dark, thick-bodied, near water in southern and southeastern Missouri. Often confused with harmless watersnakes.

Timber rattlesnake

Missouri's largest venomous snake. Wooded hills and river bluffs.

Western pygmy rattlesnake

Small and gray, with a tiny rattle you may not hear. Ozark glades and rocky woods.

Prairie massasauga

Rare and state-endangered; prairie wetlands in northwest and north-central Missouri. (The eastern massasauga is considered extirpated from Missouri.)

Telling them apart — from a safe distance

  • Missouri's venomous snakes are all pit vipers: they have a heat-sensing pit between the eye and nostril, vertical (cat-like) pupils, and a single row of scales under the tail.
  • Harmless snakes have round pupils and a double row of scales under the tail.
  • Young copperheads and cottonmouths have a yellow or greenish-yellow tail tip.
  • A triangular head is NOT reliable: harmless watersnakes, gartersnakes, and hog-nosed snakes flatten their heads when they're scared — which is why watersnakes get killed by mistake all the time.
  • Do all of this from a safe distance. You never need to get close, and you never need to handle the snake.

Why you shouldn't kill it

Every native snake in Missouri is protected, so it's generally against the law to kill one. The one realistic exception is a venomous snake that's an immediate danger right by the house — and even then, the safe, legal move is usually to leave it alone and let it move on. Most bites happen when people try to catch or kill a snake. Snakes also earn their keep by eating rodents.

Keep snakes away from the house

Keep the grass short, clear brush and rock piles, control rodents (a snake's food), seal gaps along the foundation, and don't reach into places you can't see. (Keeping a venomous snake is allowed only under strict permit conditions — it is not a casual pet.)

Snakebite first aid

If you're bitten by a venomous snake

Do this

  • Stay calm and step away from the snake.
  • Keep the bitten limb still, in a neutral and comfortable position at or below the level of your heart.
  • Take off rings, watches, and tight clothing before swelling starts.
  • Get to an emergency room, or call 911. The ER can evaluate the bite and give antivenom if it's needed — not every bite needs it.
  • If you can, note the time of the bite and mark the edge of the swelling — it helps the ER see how fast it's spreading.
  • You can also call Poison Control at 1-800-222-1222 for guidance.

Never do this

  • Don't try to kill or catch the snake — a photo from a safe distance is all anyone needs, and most bites happen when people try to handle one.
  • Don't cut the wound.
  • Don't try to suck out the venom.
  • Don't apply a tourniquet, and don't wrap it tightly with a pressure bandage — that's first aid for other kinds of snakes, not Missouri's pit vipers.
  • Don't pack it in ice.
  • Don't drink alcohol or take aspirin or ibuprofen while you wait.

Treat every venomous bite as an emergency, even if it feels mild at first.

Before you act

Missouri Porch explains; the experts decide.

Last checked: 2026-06-18. Animal facts and wildlife rules change — and a bite, sting, or exposure is a medical question, not a website question. When in doubt, make the call.

This is general information, not medical or legal advice. For a bite, exposure, or emergency, call your doctor, your county health department, Poison Control (1-800-222-1222), or 911. For wildlife rules, check with MDC.

Heads up: A triangular head is not a reliable sign of venom — scared harmless snakes flatten their heads too. When in doubt, just give any snake room.

Page feedback

See something off, missing, or unclear?

Send a quick note if a Missouri source, county office, local detail, or link needs a closer look.

Send a note