How can you tell if a catapillar is poisonous?

To determine if a caterpillar is poisonous, look for bright colors or distinctive patterns, as many toxic species use these traits as warning signals. Additionally, some caterpillars may have spines or hairs that can cause irritation or allergic reactions. Observing the plant they feed on can also provide clues; certain plants are known to host toxic caterpillars. However, it's best to avoid handling any caterpillar unless you can positively identify it.