Attack by a cat on a rat was elicited by electrical stimulation of the ventral parabrachial nucleus or the paralemniscal pontine reticular formation. The attack was quiet and it differed from similar behavior elicited at other sites in that the cat not only bit the rat but struck it with its paw. Horseradish peroxidase was deposited at the attack sites. Cells sending projections to the attack sites were located in gyrus proreus, anterior, central, and medial amygdala, the bed nucleus of the stria terminalis, lateral, dorsal and perifornical hypothalamus, as well as the central gray matter, superior colliculus, midbrain reticular formation, locus coeruleus, nucleus of the lateral lemniscus, and nucleus interpositus. Additional sites of cells of origin appeared with less regularity. This distribution of sites correlates well with the sites from which attack can be elicited or modulated.