Chickens eat bugs in all three stages adult, larval (caterpillar), and egg not to mention slugs. They also eat seeds, including weed seeds. Let your chickens loose in your garden in autumn after you ve harvested everything you don t want pecked to the ground. The chickens will gobble up every weed seed, pupa and slug they can find, cleaning up your garden for next spring. You can also let them out in early spring when weed seeds are starting to sprout and bugs are becoming active. Using them in the fall and spring should reduce your weeding and bug-hunting throughout the growing season. You can also use chickens to reduce fly populations that affect your cattle or dairy cows. If you pasture your herd using intensive rotational grazing, bring the birds in three to four days after the cows have been in each paddock. The chickens will tear apart the manure to reach fly eggs and pupae. In the process, they ll spread the manure around the field, which benefits from more even fertilization. Your cattle will have fewer flies and fly parasites bothering them, which will reduce their stress levels, reduce parasite treatment costs, and likely increase meat or milk production. If you raise your chickens more conventionally, using a permanent coop, consider attaching a greenhouse to it. A south-facing greenhouse will warm the coop during winter days, and the heat from the chickens will moderate the greenhouse temperature during the cold nights. Also, the carbon dioxide produced by the chickens will be used by the plants in the greenhouse, and insects will be eaten by the birds. Remember to use an air filter to reduce the feather dust in the air.