One of the terrible aspects (among many) regarding synthetic pesticides is that they kill all insects indiscriminately. There are actually “good” insects that are beneficial to your garden, and peticides kill them along with everything else.
Although intended for kids, this fun guide shows which insects are good to have around — for all sorts of reasons, including pollination, killing destructive insects, and even destroying slugs and snails.
And, once you’ve realized that insects are worth keeping, you can assure their survival by building homes for them. This article spells out how to do just that.