Trichoceridae, or winter crane flies, of the order Diptera are long, thin, delicate insects superficially similar in appearance to the Tipulidae, Tanyderidae, and Ptychopteridae. The presence of ocelli distinguishes the Trichoceridae from these other families. There are approximately 160 known species. The adults can be found flying in the fall and the spring and some are active even in the winter, hence their common name. They form dancing, loose swarms of mostly males. Adults can also be found resting inside caves and hollow logs. Larvae occur in moist habitats where they feed on decaying vegetable matter. They are of no economic importance.