Millipedes, in general, are not known to bite humans. They lack venomous fangs or stingers that would enable them to inflict a bite. Instead, millipedes have a defensive mechanism where they produce toxic substances or secretions, such as hydrogen cyanide or benzoquinones, which can cause irritation or discoloration of the skin. When threatened, they curl up into a tight spiral or release these chemicals as a deterrent. While these secretions may cause discomfort or mild allergic reactions in some individuals, they are not considered dangerous or venomous. It's important to note that there are thousands of species of millipedes, and some rare exceptions may possess stronger mouthparts capable of delivering a defensive nip, but these occurrences are uncommon, and most species are harmless to humans.