Spring traps can ONLY be used to trap a small number of mammals - NEVER birds - that the government (and the shooting and agriculture lobbies) lists as 'pest species' and/or non-native species that don't have the same protection in UK law as native species. Grey Squirrel (but not Red Squirrel) Brown and Black Rat House Mouse Rabbit Brown Hare (but not Mountain Hare) Mink Stoat (but only using DOC Traps, Perdix Spring Traps,  Goodnature A24 bolt trap, and Tully Traps) Weasel Edible Dormouse (but only under licence CL02)   NO OTHER SPECIES can be legally killed in a spring trap.   The Small Ground Vermin Traps Order 1958 states that "The traps referred to in the Schedule to this Order are, for the purposes of subsection (5) of section 8 of the Pests Act, 1954, hereby specified as being adapted solely for the destruction of rats, mice or other small ground vermin" but the Act does not specify what species constitute 'small ground vermin' and may include the Wood/Long-tailed Field Mouse Apodemus sylvaticus. Approval to trap ferrets with the DOC 250 spring trap was removed in 2021 because of the risk to non-target species. They must now be caught using live capture traps. It is illegal to kill birds in spring traps, but note that live capture 'spring-loaded net traps' are legally used to trap birds for the purpose of ringing under licence.