clover trap
n.— «USDA workers are using steel-framed mesh traps that are easily transported and assembled. Baited with corn and placed along runways, the “clover traps,” as they are called, drop the open door when an animal gets inside the trap and breaks a piece of 15-pound test monofilament to spring the trap door. The soft-sided traps are able to hold the deer without causing them much injury.» —“USDA reactivates TB program for deer” by Bob Gwizdz in Hillman mlive.com (Michigan) Feb. 17, 2007. (source: Double-Tongued Dictionary)