These surveys are likely to be recommended where rivers and streams are affected by development in areas where the white-clawed crayfish is known to be present. Crayfish can be collected by setting funnel-shaped traps along the banks of streams. These traps are set overnight and contain bait to attract the crayfish, which are nocturnal. Other techniques include manually searching under boulders and torchlight (night viewing) surveys. White-clawed crayfish surveys are undertaken between July and October, and during April. Between November and March, crayfish activity is reduced, and surveys are not so effective. As crayfish breed during May and June, this precludes survey work in that period.