7. Pygmy rattlesnake

The southeastern pygmy rattlesnake, found in the US from Florida to North Carolina and west through Texas, also makes the list of animals that have improved human medicine. While this snake is too small to leave a dangerous bite, its venom has some amazing properties.

A molecule in the venom leaves prey bleeding abundantly, their blood unable to clot. This could speed up chemical reactions occurring in an organism so quickly that they can kill the prey of these small snakes.

According to experts, these substances that can genuinely do harm could actually be drugs at different doses. We’re talking about a molecule from rattlesnake venom that was developed into eptifibatide, a drug that prevents blood clots from forming. Eptifibatide is used to treat advanced cardiovascular disease, especially in patients at higher risk for sudden heart attacks.