Instructions
Count the number of pairs of legs on your specimen. All arachnids have four pairs of legs, while insects have three pairs.
Determine if your specimen has a hard exoskeleton and jointed appendages for walking and other purposes.
Look for antennae and wings, features on other arthropods but never on arachnids.
Learn how to identify each type of arachnid. The most common are spiders, which have eight appendages and eight eyes. Scorpions are the largest arachnids, with a sharp stinger at the end of their tail used to paralyze or kill insects and small animals. Much smaller are mites and ticks, which are parasites and live off the blood and tissue of animals and humans.
Look for the number of segments on the body. Arachnids are two-segmented animals consisting of a cephalothorax and an abdomen. The cephalothorax is a fusion of the cephalon which is the head and the thorax.
How to Identify Arachnids
There are 11 orders of arachnids, including scorpions, mites, ticks, harvestmen, pseudoscorpions, whipscorpions, solpugids and spiders. Evidence suggests that arachnids, a type of arthropod, were among the first animals to live on land, some 400 million years ago. Here's how you can spot them.