What makes holes like there drilled?

Sounds like a mole. They're busy little fellas.

Moles , get stuff you put in hole for them to eat. But if you have pets don't use it. Put hose in holes & let water run in & they will go away in time. Good luck.

Call your County Agriculture Agent. Those county offices can help with lots of things.

Moles, or any burrowing varment...cats help, heaven's we used too fill the holes bk up n trap them.. try garden store. they have what u need..

It is moles that are most likely going after grubs in your lawn.

http://homeguides.sfgate.com/rid-yard-moles-fast-48707.html

http://pestkill.org/moles/in-your-yard/

http://www.bhg.com/gardening/pests/animal/get-rid-of-moles/

Squirrels will dig holes also. They think they are burying their acorns for later but then forget where they planted them.