This disclosure discloses a light-emitting device. Netting attached to at least one frame member so that when release mechanism is tripped by animal entering trap, at least one frame member pulls netting over animal as at least one frame member falls to ground when tension is released. Using the disclosed cost function, the result residual corresponding to the optimal motion vector can be better compressed than that of other candidate motion vectors. The switching matrix is adapted to combine the electrical output signals provided by the electrically isolated PD sections in a plurality of different manners, in dependence on which of the plurality of different switch configurations is selected.