Meet the world's most gruesome killer. The assassin bug proudly displays the exoskeleton of its kills (after it sucked out the innards as dinner) on its back! But there's logic to that macabre madness:
... the assassin bug’s width means it can pile them high, creating a mound of over twenty ‘shells’. The exoskeleton of ants is made of chitin, a particularly sturdy substance which can provide cover for the assassin bug for weeks.
The heap is stuck together by a sticky secretion. As it is usually larger than the bug itself, should another insect decide that the assassin would be good for its next meal it serves as a readymade getaway plan. The attacker goes for the larger part (the hollow exoskeletons) which are then simply shed, allowing the assassin bug to beat a hasty retreat.
Ark in Space has more pics: Link