Notes that in typical laboratory settings, the defensive reactions of animals appear to be limited to freezing, fleeing, and attacking. However, 95 naive adult male hooded rats tested in the presence of bedding material incorporated it into a striking and adaptive behavioral sequence. Ss shocked once through a stationary prod buried this shock source, even when the shock-test interval was 20 days. Moreover, the burying seemed to be guided specifically by the relation between the prod and the shock; Ss shocked through a grid did not bury the prod, and Ss shocked by 1 of 2 identical prods buried only the shock prod. Thus, the usual assumption that the rat's defensive repertoire is limited to a few simple behaviors appears to have been shaped by the constraints of standard testing environments rather than by the actual propensities of the rat. (6 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved)