Multiple diseases can be contracted from a single tickbite. Ticks are bloodsucking external parasites that feed on humans, wild and domestic mammals, birds, reptiles and others. The longer an infective tick feeds, the greater the chance of infection. Ticks are not insects. Ticks have eight legs as an adult and two body segments, whereas insects have six legs as an adult and three body segments.
Ticks are arachnids, as are chiggers, spiders and mites.
The egg hatches into a larva. It feeds and molts into a nymph. A nymph has eight legs and no sex differentiation. It then feeds and molts into an adult. The adult is differentiated into male or female.