The trap (1) has an inner space (2) defined by a peripheral wall (3) with a plain bottom lower wall (3a) and roof upper walls (3b, 3c). A sheet (4) with an adhesive upper face is arranged on the lower wall. A suspension unit (5) supports bait in the inner space of the trap. The suspension unit is precut in thickness of a part of the lower wall, which is covered by the sheet. The suspension unit is arranged for holding a bait reservoir (51) in the inner space of the trap, where the trap is realized in a foldable material foil.
