The photos are not very clear but I'd suspect worm castings. So nothing you want to get rid of... it is just the very nutrient rich poop of garden worms :-) Just rake to smooth or ignore.

Call your local Purdue Extension office to see if, by any chance, mole crickets are an issue in your area.

Were the pictures taken recently?

Thanks for the replies.. To add some information, they are appearing in soil that has a lot of clay in it. They were taken last June.

Possibilities are earthworms, mole crickets, and some variety of solitary wasp. If you lived along a salt water coast, I'd add fiddler crabs to the list, lol.