The farm we purchased 6+ years ago is just starting to see fireflies and bats come back. We look at dusk visible bats to gauge our bug population. We stopped spraying and are allowing fields to go back to a mixture of natives and grasses. Also started mowing strips instead of bush hogging the whole field during the summer to give shelter to animals and insects. The biggest impact we have seen is that we have more of a "bug balance". The first two years we were here the garden plants were destroyed by pests. Now we have about a 20% reduction in garden production. We do not spray or fertilize. We have also discontinued the previous owner's habit of putting chicken litter (from commercial poultry facilities) on our hay and grazing fields. We have not been able to measure that effect yet.