Strange Find

Question

I found a claylike mound in my garden. It was stuck to the ground. When I removed it and cut it open the inside was filled with compact mulch and pebbles. What could it be?

Answer 1

I suspect is is crayfish. You will probably see more mounds. Here is more information:

https://www.gardeningknowhow.com/plant-problems/pests/animals/getting-rid-crayfish-in-lawn.htm