In his 2008 book "Only A Theory", biologist Kenneth R. Miller challenges Behe's claim that the mousetrap is irreducibly complex. Miller observes that various subsets of the five components can be devised to form cooperative units, ones that have different functions from the mousetrap and so, in biological terms, could form functional spandrels before being adapted to the new function of catching mice. In an example taken from his high school experience, Miller recalls that one of his classmates...struck upon the brilliant idea of using an old, broken mousetrap as a spitball catapult, and it worked brilliantly... It had worked perfectly as something other than a mousetrap... my rowdy friend had pulled a couple of parts --probably the hold-down bar and catch-- off the trap to make it easier to conceal and more effective as a catapult... the base, the spring, and the hammer. Not much of a mousetrap, but a helluva spitball launcher... I realized why [Behe's mousetrap analogy had bothered me. It was wrong. The mousetrap is not irreducibly complex after all.