And yes, a lot of dogs eat poop. The fancy word is coprophagia, which sounds dramatic, but most of the time it’s not some big medical mystery. It’s usually behavioral.

Understanding the Context

Dogs are scavengers. They didn’t ... Why is a just a rather odd wh -word. Its distribution is very limited -- it can only have the word reason as its antecedent, and since it's never the subject it's always deletable.

Key Insights

Consequently it behaves strangely, as you and others point out.