Lasioseius is a morphologically diverse genus, with more than 100 described species found on rotting organic substances, under bark, and in forest litter, moss, soil, nests of small mammals and birds, bracket-fungi, tree-holes, stored products, warehouses, and hay. Some species are omnivorous, feeding on microarthropods and on fungi, while others are only predatory (Enkegaard and Brodsgaard, 2000; Walter and Lindquist, 1989). Several species have been collected in beehives. Among them, one species, Lasioseius penicilliger, has also been found in bumble bee nests. These species are habitat generalists and probably do not have a particular preference for bee nests.