The mice population has started to boom again and they have a favorite coop. Unfortunately, one male & female in that coop were in REALLY bad shape when I figured this out. Oddly they did not show the same "dirt" that everyone showed on the rear. Then hen was suprising all together as it took for her to sit in the nest having muscle spasms in her neck for me to see that something was wrong. And the rooster.. well.. he didn't have a sign of one on his rear... but under his right wing was the worst I've ever seen. Both were nearly lost when I found them. THIS is a good reason NOT to have too many chickens! I've tried to cheat here and there... only using Ivermectin or Selamectin on those affected, dusting Sevin on everyone else & their coops. I use DE sparingly and for a year never had a single mite, but I've been battling off and on for a couple months now. So... I have a new erradication plan, which of course includes treating EVERY SINGLE BIRD - we're talking around 50 right now, but better NOW than before I start hatching this season. I know that Selamectin works almost instantly but it's PRICEY, and not suitable pricewise for every single bird! I have used Ivermectin for cattle but not the Eprinex... the lot expired in the summer... perhaps it's lost its effectiveness. So my new plan is as follows... support & suggestions welcome. Yes it may be overboard, but I'm SO TIRED of this on and on stuff. Day 1 - Eprinex Pour On AND Flea/Tick baths for anyone who we can see mites on. (permethrin based) also Ag lime all sand in coops. Day 3 - Sevin Dust & DE chickens & coops & bedding Day 4 - HEAVY Cayenne Pepper & garlic in the food (both make undesirable host) Day 5 - Flea & Tick Spray on the birds & the coops (permethrin based) Day 7 - Eprinex Pour On Day 10 - Sevin Dust & DE all birds & coops Day 13 - Repeat Cayenne Pepper & garlic Day 14 - Flea & Tick Spray if they are finally controlled OR Eprinex again if I still see a problem. ALL NESTS will switch to pine shavings, DE & tobacco leaves (shred cheap cigars if nothing else). This BETTER DO IT!!! Or I might just give up on this chicken path and stick to only a few laying hens. All these treatments are PRICEY!!!! added: both of the afore mentioned chickens are now residents in my living room. The hen has very few feathers are apparently she was not allowed to finish her molt (I had an apron on her and didn't notice) due to the mites. The roo is doing better now that they both have had a LONG flea bath. He'll go back out to his coop once I begin the process above. SHE is staying inside until she grows her feathers on her back or until the weather warms up to a consistent 50*F or so.