[candiodari]

I can't state how wrong you are. Believe it or not, different classes of life have different cells with different DNA. They use different pathways for almost everything.

As such, they are not equal. Specifically, insect cells are generally "more advanced" than ours (have more recent "basic" genes, more accurately adapted to their environment, tougher, ...), a lot smaller, ...

Bacteria are far more different from us than that, as are spores, other plants, ...

So yes, there are a LOT of compounds that throw a wrench into, say, insect procreation but have no known effect on humans.