How do I get rid of crayfish in my lawn?
There is no good answer. Crayfish chimneys in lawns are associated with a high water table or heavy, low-lying soils around ponds and streams. Problems are worse in wet seasons or years. Anything that reduces soil moisture or water retention, such as draining and tiling, may help. In areas with a high water table, there is not an alternative.
There are no pesticides registered for crayfish control because of concerns about ground water contamination.