The reason I said mites because I had seen them around my girls’ eyes too and I’m already trying to treat them for mites. I guess it’s nothing to worry about though?I'd check them with the photos in the link I gave you to see if they do have lice/mites.
It's also possible that they are just a species of fly or gnat that has hatched where you are and are swarming right now (I just can't see it with enough detail to guess). Where I am we have gnats that get around their faces and eyes and drive them crazy during the summer months. Being that there tends to be droppings where chickens are, flies are going to be attracted. I planted rosemary bushes in my run and the chickens lay down in them and it seems to help with the gnats some. You may be able to call your local agricultural office and get info on what particular insect it may be in your area right now.