House crickets are about 3/4 to 7/8 inches long and yellow brown or straw colored with three dark bands across the top of the head. This is an outdoor and indoor pest.
There are two main varieties of crickets, the cave cricket and field cricket. The cave cricket is the light brown monstrosity that you see on the walls, floors, and sometime ceiling that have long antennae, humped back and make no noise. The field cricket is you more typical black to dark brown insect with an elongated body that makes the well known cricket chirp.
Both types thrive in cool, moist environments and cause no serious harm to you or your family but can be annoying, frightening, or embarrassing depending on the individual.