Because they are arachnids, not insects, ticks most closely resemble other arachnids, such as pseudoscorpions or spiders with rounded abdomens. However, some insects, such as beetles, also resemble ticks..
Pseudoscorpions look like ticks with have large, crab-like pincers. Although the tiny arachnids have venom glands in these appendages, they are far too small to harm humans. A variety of spider species resemble ticks, except that ticks lack the large pedipalps that spiders possess. Pedipalps are the set of appendages located near the faces of spiders.
Insects with appearances similar to ticks include shield bugs, stinkbugs and assassin bugs. These insects have large abdomens, which may be mistaken for the abdomen of a tick. Stinkbugs and shield bugs are completely harmless, but assassin bugs inflict a painful bite. In rare cases, assassin bugs can transmit Chagas’ disease.
Like all arachnids, ticks possess eight legs. The first step to identifying a tick is to count its legs. If the animal has six legs, it is some type of insect. Additionally, ticks lack antennae and possess two body parts, while most insects have three. There are hard ticks and soft ticks. Unfed hard ticks resemble flat seeds while soft ticks have the appearance of raisins.