The family contains more than 2,000 species of medium to large nocturnal moths. Several are important forest pests and live gregariously. The larvae of some species form tents.
The adults have a stout body and wings densely covered with scales. Most species have broad wings. The proboscis is absent or much reduced. The caterpillars have long hairs.
The following genera and individual species are currently entered under Lasiocampidae: