One really big drop per pound might be enough. A normal drop is only 0.02 ml, so not enough.This is my personal experience, but I figured I'd share it. When I did the math, I got that it was about 1 drop per pound of bird. It actually covered a tiny bit more than a pound with a drop. I know, it's crazy, but I went out & stood on the human scale with several of my chickens & got a good feel for what they felt like pound wise, lol! And then I dosed each bird by feeling them and dosing accordingly. It worked for me for chicken mites & for the worms they had. The birds I have are easter eggers, welsummers, olive eggers, silkies, polish, cochins, houdans and d'uccles. I did only 1 drop for my tiny d'uccles, and I did 4 drops on my easter egger rooster (my biggest boy), who is 4.5 lbs. I dosed them all twice, 10 days apart. I hope this helps anybody!