The ensign wasp is one of the odder insects found occasionally in homes.  A small insect, only 5-7 mm long, it does not sting or bite.  In fact, it does no harm; but it is a beneficial parasite of at least three household cockroaches, the American cockroach being the most common. Ensign wasps are experts at locating not the cockroaches themselves, but the egg cases (oothecae) that cockroaches deposit.  According to one account, when the female ensign wasp encounters a cockroach egg case, she first taps it with her antennae, presumably… Read More →