Mites
There are numerous mites (Rat mites, chicken mites, bird mites . . . ) that are capable of invading our homes. Mites that originate from animals can easily enter a home (due to their tiny size) through tiny entrance points around windows, doors or any other space large enough for them to squeeze through. Other mites that originate from plants do not migrate as well as other mites but they can enter our homes by hitching a ride on anyone that works in gardens, hot houses, nurseries or even children playing outdoors. Most plant mites do not bite but they can be an annoyance when their numbers are high. These mites can also cause an allergic reaction in some people.
Most mites are 1/200 to 1/25 inch long, oval, without antennae and grayish-black to red. Their mouth parts are grouped in front of the body, resembling a head. Adult mites have four pairs of legs. The follicle mite is more worm-like. Some mites appear as barely visible red and gray, slow-moving specks, while others are microscopic, requiring optical equipment for identification.