Any arthropods that share the same characteristics as spiders are known as arachnids. Other arachnids, or spider relatives, include ticks, daddy-long legs, scorpions, and mites. The difference between spiders and insects is that all spiders can produce silk throughout their lifetime. However, just a few insects can produce silk, and then at only certain times during their life. Spiders use silk to build webs and other types of snares and egg cases. Spiders are predators, feeding mainly on insects. Spiders are considered beneficial because of the large number of insects they prey on, including a number of pest species. All spiders have venom and are therefore venomous. However, most spiders are harmless to people. They are very shy and usually remain hidden in undisturbed areas. Many are active only at night. They are not aggressive and they will try to escape when confronted. Few spiders bite, even when coaxed. Fortunately, the bites of most spiders are less painful than an average bee sting.
Crab spiders are common spiders outdoors, but are not usually seen indoors. They are small to medium-sized spiders (1/4 inch long) ranging in colour from yellow or red to brown. The first four legs of these spiders are crab-like, being held out to the sides. They are also usually longer than the back four. Crab spiders can walk forwards, sideways, or backwards. While many hunting spiders actively pursue prey, these spiders wait motionless and ambush insects that pass closely by. Outdoors, the spiders are often found on flowers but are also seen on stems or leaves.