You are most likely better off with them free ranging. Confinement will make a lice breeding ground. I would dust more often for an extended period to break up the lice breeding cycle. If all else fails, try a drop of pour on cattle wormer on their backs. They'll get a few months of protection.There will be residue in the eggs and meat, but it isn't harmful to vertabrates so as long as you don't sell them or the eggs you're fine.

Yes, you should be able to get dewormers at the feed store but then you have to deal with withdrawl times before it is safe to eat the eggs or meat. Anything that is strong enough to be effective will leave a residue in the meat and eggs. I use food grade diatomatious earth as a feed additive. It has no residue, it kills any worms in the digestive system, and reduces the amount of flies that can breed in the manure. I buy it from Garden Harvest Supply and after shipping costs, it's about the same as going to the feed store.

Ive raised the Cornish x growing up as a kid so did my parents. I really don't like them because you have to process them all out by the time they are 8 weeks old, and they produce much more waste- all they do is eat and poop and to even begin to keep them healthy you have to do management practices such as making them walk to there feed and water dishes, plus restricting there food to slow there growth so less of them have heart attacks or suffer liver failure. Last year i raised Delawares. They rock. I processed some of them at 2-3# at about 12 weeks and some of them a bit bigger. so no pressure to get the all done by 8 weeks. They don't die off of health problems. They don't eat themselves to death given a choice. They have a nice white feather body making plucking a clean carcass easy. Did you know before the Cornish x's Delawares where used by most poultry meat produces here in the USA. As a good aside I kept a few of the hens which are now laying very well.

Best way to prevent ticks in a yard is proper lawn maintenance by keeping the grass cut short and manicured. Ticks and Chiggers need tall grass to climb up on to catch a ride with passing host. If you have a serious problem, you need medicine. Unfortunately the government banned the most effective herbicides for controlling ticks. Seems a bird life is worth more than your life. Anyway there are still some moderately effective herbicides that you can use in the form of sprays and granules. The best today is a professional product in most sates called Bifenthrin (Talstarî, Orthoî products). A pyrethroid insecticide made from synthesized Pyrethrin (Daisies). In some states you can buy it in Box Stores or online at DIY Pest Control websites. Next in line is Permethrin (Permethrin, Mosquito-Offî, Astroî, Orthoî products, Bonideî products,, Tengardî SFR, others). A pyrethroid insecticide mainly for homeowners. Another synthesized Pyrethrin product. Pyrethrin . (Pyrenoneî, Kickerî, Organic Solutions All Crop Commercial & Agricultural Multipurpose insecticideî) Pyrethrins are derived from the chrysanthemum flower. They are often combined with the synergist piperonyl butoxide (PBO), which increases the killing power of pyrethrin, or insecticidal soap. Only a combination of pyrethrin and PBO with either insecticidal soap or silicon dioxide (diatomaceous earth) was found highly effective against ticks. Thorough coverage appears vital for these materials to be effective as there is little residual activity. Two applications are required. The two synthetic Permethrin and Bifenthrin products have residual properties which means only one application is required to kill Adults, Larvae, and future Larvae that hatch from eggs. The organic Pyrethrin product degrades in 24 hours and requires at least two applications two weeks apart. One app to kill Adults and Larvae, and another app to kill Larvae that hatch from eggs. Actually there is one better than all of these we farmers use on our pets but is very expensive and restricted to small areas due to cost called Carbaryl (Sevinî). Carbamate insecticide. Environmentalist hate this product as much as they hated DDT, Diazon and Malathion which were extremely effective but now banned.