i had never wormed my chickens before and i decided why not? i just got chickens and chicks to add to my flock and decided to worm all of them. i used Diatmaceous Earth. you mix it with their feed. but i noticed they werent eating much of it because it will fall off the food because it is powder. so i mix lots of water in with layer feed to where it is wet but not watery. i mix about 1 tble spoon for 7 chickens. they eat it up fast! you can also put it on their skin to kill mites. you can put it in the coop nest and nest boxes even water. just make sure you only add a little to the water. you feed it to them with wet feed every day for 4-5 days giving less every day. then once a week for one month. then once a month for as long as you want. you can put it on their skin as much as you want. it works for chicks too just give alot less. i would only give it too chicks older than 7 weeks. it works for dogs and cats too. pretty much all animals. i got it from tractor supply.