"Some species of carpenter ants infected with metacercariae of the fluke Brachylecithutn mosquensis, are more obese than noninfected ants and, unlike the latter, they do not conceal themselves but crawl on exposed surfaces where they are easily found by birds that are the next hosts of the fluke. This behaviour seems to be a remarkable example of an animal that sacrifices its life for its parasites. The 'sacrifice', of course, is induced by the parasite."