This is an overview of poisonous bugs and other animals prevalent in the United States. Each species is linked to a full article on the topic of toxicity to that particular animal. Also check out: Poisonous Plants and Berries.

Poisonous Bugs


Centipedes are poisonous. They have maxillipeds, which are a special pair of front legs that can wrap around their mandibles and inject venom into a person or an animal. When they catch their prey, they release poison from a gland below their fangs. Although their venom is poisonous, it isn’t normally life-threatening for people.

Garden Spider

Garden spiders are poisonous. However, a more precise term to use is venomous, as the garden spider injects venom into its prey in an effort to paralyze it. Paralysis usually occurs in smaller prey such as insects. However, humans and other animals react to the venom differently.


Unlike centipedes, millipedes are not poisonous. However, there are species that have glands that produce fluids that can trigger an allergic reaction in some people. These fluids contain hydrochloric acid, which can damage the skin. It can also harm your eyes. You should wash your hands with soap and water and use alcohol if you come in contact with their fluid.

Monarch Butterfly

Monarch butterflies are poisonous. Their poison isn’t potent enough to harm humans, but they can make their predators sick, including frogs, grasshoppers, lizards, mice, and birds. Their bright colors do warm these critters that they are dangerous. The Monarch absorbs the poison and stores it when it is a caterpillar and eats the milkweed plant. This is the only place they will lay their eggs.


While salamanders can have bright colors, their bite is not poisonous to people. However, their skin is poisonous, so you should always wash your hands and avoid touching your mouth or your eyes if you touch one. They secrete this substance from the glands in their skin, and it can cause irritation. They are harmless if you don’t touch them.

Non-Poisonous Bugs