These are the German, brown-banded, Pennsylvania wood, Oriental, and American cockroaches. Cockroaches usually prefer a moist environment, but many species also like a relatively high degree of warmth. The insects are mostly scavengers and will feed on a wide variety of foods. They are especially fond of starches, sweets, grease, and meat products. For many species garbage is a principal food source.
Cockroaches are mostly active at night, when they forage for food, water, and mates.
During the day they hide in cracks and crevices and other dark sites that provide a warm and humid environment. Their relatively wide, flat bodies enable cockroaches to move in and out of cracks and narrow openings with ease. They may be seen during the daytime, particularly if a heavy population is present or if there is some other stress, such as a lack of food or water or an application of pesticides. The German cockroach is the most economically important urban pest. It is also the most common cockroach species in houses, apartments, restaurants, hotels, and other institutions.