Are Centipedes and Millipedes Dangerous in the United States?

In the United States, centipedes and millipedes are common household pests, but their levels of danger can vary significantly. Understanding whether these creatures are dangerous and the nature of their potential threats is essential for ensuring safety and proper handling.

Centipedes: Venomous and Potentially Harmful

Centipedes are carnivores and possess venom, making them potentially dangerous. However, their venom is generally not life-threatening unless someone has an allergy to it. Typically, a centipede bite results in significant pain comparable to that of a wasp or bee sting. The house centipede, a common species, is generally harmless, but larger tropical centipedes can pose a more serious threat, especially to small children. Reports of fatal bites are rare, but it’s important to respect these creatures.

Millipedes: Safe Though Not Without Defenses

In contrast, millipedes are largely harmless, being exclusively vegetarian. They feed on decaying organic matter, such as rotting leaves, and are not known to bite or possess venom. When threatened, millipedes curl up into a ball or excrete a foul-smelling liquid, which is irritating but not toxic if consumed. Some species may produce fluids that can cause minor skin irritation if the millipedes are crushed and their fluid comes into contact with sensitive skin.

Behavioral Comparisons

Centipedes are primarily carnivorous and have venomous appendages called maxillipeds that can inject venom. They will only bite when they are threatened or disturbed. Most centipede species, even those with venom, rarely bite, and the house centipede's bite is generally not painful. In rare cases, larger tropical centipedes have caused severe reactions, occasionally resulting in fatalities, especially in small children. Adults, however, should not typically be at risk unless they have an unusual allergic reaction.

Millipedes, on the other hand, are almost exclusively vegetarian. They do not bite or possess venom. They protect themselves by curling into a tight ball or releasing a foul-smelling, irritating fluid. If millipedes are crushed and their fluid comes into contact with the skin, it may cause itching and irritation, but these effects are generally not serious.

Both centipedes and millipedes are typically safe if handled with care. Exposing them to excessive handling or consuming them can lead to different forms of irritation, but their inherent danger is relatively low. Proper handling and respect for these creatures can help in coexisting with them in households without undue risk.