Abstract: A trap includes a cage defining a capture space having an opening in an upper end of the cage. A cover is pivotable about a pivot axis between a closing position closing the opening and a revealing position revealing the opening. The cover includes a first end and a second end having a spacing to the pivot axis smaller than the first end of the cover. A counterweight device is mounted to the second end of the cover to bias the cover to the closing position. The cover moves to the revealing position when an animal moves to the first end of the cover, such that the animal falls into the capture space.