Answer: It sounds like you're located in prime crayfish habitat - moist soil, water readily available, etc. I suggest that you not try to poison them, since the water table is likely high in your yard, and you could pollute the groudwater that you will eventually drink. You can try to construct a "moat" around your yard to prevent their entry. Dig a trench a foot deep and a foot wide, and fix a slick board at a 45 degree angle over the trench. They'll encounter the board and not be able to cross onto your property. The only other suggestion I have is to contact your state Fish & Wildlife department to see if they can help. Let us know what happens so we can pass your experience on to others troubled by crayfish!
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