1.   Bait stations lure the termites to a chemical that kills the insects by stopping them from shedding and replacing their external skeletons.

2.   The arms of the creatures called Ophiocoma wendtii, he found, were studded with hundreds of tiny bones that make up the protective armor of its external skeleton.

3.   They have relatively weak wing muscles, and their thoracic cuticle plates are not fused together to create a rigid external skeleton.

4.   They set off allergic reactions when their feces pellets and jettisoned external skeletons are breathed in.

5.   Brine shrimp in Great Salt Lake supplement their diet of green algae by eating their own castoff external skeletons, scientists from Poland and Utah have concluded.