
They are a brownish, humpbacked cricket, have very long antennae and are wingless. In the wild they are found in caves and cave-like habitats. They like dark, moist environments, which is why they are sometimes found in basements and are a sign that you have a moisture problem! They are easy to discourage, just eliminate the dark damp habitat they prefer.
References:
Camel Crickets. Insect Identification Laboratory, Department of Entomology at Virginia Tech.