Thanks for the suggestion but it is not a rabbit . I am talking single individual strands of long grass or daylily leaf in a single hole the size of maybe the end of a pencil point .Whatever it is pulls the single strand in after themselves and blocks the miniscule hole with the strand of grass

Signet., I asked Eric and he thought probably a mouse or vole. I've found a lot of those small holes in the garden but never one that was plugged up. I'd guess even a chipmunk.

A hole that small seems like some kind of insect, but I don't know any that try to cover their hole.

Maybe ants? I've seen them pulling things down holes.

Nancy , and Hu-98873749 ( Marg is that you?) yes, I am guessing an insect but what ? I have not seen any particular signs of ants ( and they follow the same trails all the time and this is really very random ) it has no rhyme or reason or pattern ........just every so often a strand of long grass or daylily leaf is pulled down into the ground. I thought it might be sod webworm but the blade of grass does not appear to be chewed at all ..........so I am totally lost as to what it might be .

Check with your Extension Agent.

We don't have extention agents here Dick .