"If you're an adult and you get the poison in your finger, it just stays, and fires your pain nerve," said Dr. Leslie Boyer — no relation to Don Boyer. "It locks the nerve in the on position."
Leslie Boyer, who is medical director of the Arizona Poison and Drug Information Center, said that the tiny sting will "send shooting sensations up your arm." If you're clumsy enough to tap or bump that finger on anything, the pain instantly amplifies.
"You just give it a tap and you're screaming in pain," said Leslie Boyer. "Just that one little spot hurts like heck, it radiates up to your arm pit with this throbbing pain — but there's nothing to see."
Boyer says that since her practice sees so many painful stings and bites, "I tend to give out morphine like it's candy."
While this reptile has a poisonous bite, it doesn't actually induce much pain. Sure, it stops you from breathing, but for the venom to really make you scream, it needs to get into your eyes.
Spitting cobras have perfected the art of defense by shooting venom into an attacker's eyes, which creates a blinding, burning pain. Like many other pain-inducing animals, the reason for the agony is to keep attackers away, rather than to stage an offensive.
Van Wallach was unfortunate enough to get the spitting treatment from a cobra in the Philippines.
"It is excruciating," he said. "The only way I could relieve it was to pour milk into my eye about every 15 minutes. I was blind for about four to six hours."
The cobra's venom contains a mix of nerve poisons, tissue-destroying chemicals and other nasty compounds designed to elicit severe stinging. In worst case scenarios, it can lead to permanent blindness.
Should you ever encounter a spitting cobra — which is unlikely as they are fairly rare — make sure to keep a good 10-foot distance away from it. Their venom can shoot about four to eight feet.
This colorful, solitary wasp uses its stinging power to paralyze large tarantulas as food for its young. While the insect is not aggressive and rarely stings humans — "you really have to force them to sting you," said Leslie Boyer — the experience is fabled to be one of the top most painful stings out there.
According to sting expert Schmidt, the tarantula hawk rates just below the agonizing bullet ant.
"When that one when it hits you, it almost feels like you've been hit by a lightning bolt," said Schmidt. "You'll be screaming and writhing in agony. … It feels like every gland in your body is purged of all its hormones, you'll feel absolutely drained from the experience."
Unlike other animals on this Top 10 list, the tarantula hawk's venom is not for defense, but for paralyzing its much larger prey, tarantulas. The mother wasp lays a single egg on the comatose spider, dooming it to a horrific death. The egg hatches into a hungry larva, which then literally eats the tarantula alive, using it as a food source as it grows.
In terms of a perfect combo of pain and lethality, the homely stonefish's sting may take first prize.
The stonefish, found in the rocky, shallow waters of tropical oceans, has several extremely sharp spines along its back. Hapless waders can easily mistake the well-camouflaged fish for a rock or hunk of coral — and if they step on the animal, the spines will puncture the skin and inject a complex and deadly venom.