We can all be David

The little ones are often mightier than those four times their size.

A Honey Badger can fuck up a lion given a chance, and enough Red Bull ;)

Also, for those who are really literal, the song can be seen as shorthand, we are all mighty little humans.

Human does not mean human being or person, or people, it means Humanity, only those with love in their heart are truly human, and guess what, that means a lot of what you consider Animal are far more Human than those you see as people.