Carabid beetles can go one of two routes in getting past a snail's tough shell to the gooey body inside. Large-headed carabid species chomp through snail shells with their powerful jaws, whereas small-headed beetles stick their heads through the shell's opening to feed [above]. Their diversification was driven by the two possible feeding strategies¿forcing or fitting¿and the tradeoffs they entail, say researchers publishing in the journal The American Naturalist.