Most caterpillars are safe to handle but some can be dangerous to hold because they may trigger allergic reactions/anaphylactic shock or rashes, or they may sting or eject/ooze spiky hairs or even poisons. It is important to identify the caterpillar before attempting to touch or hold it; some, such as the puss caterpillar, hickory tussock or saddleback caterpillars can hurt you or make you very ill. Use a caterpillar guide or online images if you are not sure what the caterpillar is before handling it.