The slits act as non-return devices, and once an animal is captured, escape is virtually impossible. However, funnels remain open and, in most cases, the captured animals can find the opening by trial and error then eventually escape.
The slits act as non-return devices, and once an animal is captured, escape is virtually impossible.However, funnels remain open and, in most cases, the captured animals can find the opening by trial and error then eventually escape.