Get something that will do some good, like Valbazen, I consider that one of the best, liquid Safeguard for goats is a good one too. Dose them all and then repeat it in 10 days to clear out anything that hatched in the meantime since the meds don't kill worms in egg or cyst form. The feedstore people may try to sell you Wazine but that is only going to get the roundworms and there's a lot more your chickens can pick up besides that. You might consider deworming them on a regular schedule, once or twice a year depending on the climate where you live.