Most black and yellow caterpillars, like the black swallowtail caterpillar, pose no harm to humans.
However, some species have evolved potentially painful defenses. The most common is a toxic chemical that is released from urticating hairs or spines on the caterpillar. These stinging hairs are hollow and contain venom that can be irritating.
The severity of the sting depends on the species and how sensitive you are to the venom. Some people may develop a rash and welts, while others may experience no reaction at all.
Are black and yellow caterpillars poisonous to dogs?
Many caterpillars are poisonous to dogs. The black and yellow striped ones can be toxic to both dogs.
They release tiny barbed hairs that can cause irritation and even painful rashes when they come in contact with skin. Some people experience dizziness, nausea, or difficulty breathing from the toxins.
The best way to prevent dogs from being exposed to poisonous caterpillars is to keep them away from plants where they often live.