A trap (1) for catching animals, in particular muridae, is provided with a tank (2) and a passageway (8), which extends above the tank (2) from an entry (10) and has, at the end, a container (13) for a bait； the floor of the passageway (8) is defined by a gangway (3), which opens to let an animal fall into the tank (2) and is provided with two trapdoors (14,15) hinged to one another； the first of said trapdoors (14) is hinged about a horizontal axis (16), so as to tilt from a substantially horizontal position during the opening of the gangway (3), and has a counterweight (18) to reclose the gangway (3)； the gangway (3) has an attach device (24) which connects the second trapdoor (15) to a fixed retaining device (25), so as to support the first trapdoor (14) in its substantially horizontal position even when the first trapdoor (14) is subject to a weight； the attach device (24) is releasable when the weight rests on the second trapdoor (15).
