it's all in what they eat. We eat tons of mammals like cow, pig, deer, etc. but we don't typically eat other mammals like squirrel, rat, or coyote. similarly, we eat tons of birds like chicken, quail, and duck, but we don't eat other birds like vulture, eagle, etc. this is because the animals that we do eat have a diet that makes them healthy meals for us (broadly speaking). animals that feed off of carrion or meat are typically not so healthy for us, so we avoid them.

The bugs pictured eat literal shit. we do not want that in our systems.