Honey bee with Varroa mites. This adult worker honey bee (Apis mellifera) has two parasitic mites, Varroa destructor (brown) on its thorax. The mites replicate in a bee colony. The female mites lay eggs in a brood cell, and after hatching, the young mites attach to the developing bee. The mites feed on the bee's haemolymph, the blood-like fluid that bathes its cells and organs. As the bees have no defence against the mites, an infestation usually kills the entire colony.