I once read a science fiction novel. I cannot remember the title or really much about the gist of the whole story.
One thing that struck with me and which has remained with me throughout my life is a line in it that talked about what aliens to this planet, learning about it prior to contact and/or invasion, is that they found it totally ‘alien’ to them that they (Earth humans) actually killed their young by aborting them before they even reached gestational term.
There was a science fiction story about people aborting their kids up to age 15 or something. Kids scramble and hide when the abortion truck comes around.