Ha-de-das

I am just wondering if Hadedas can actually see underground. Have you seen how easily they pluck the earthworms from the lawn. Just one hit with that long crooked beak of their's-strait and true and out comes the worm-one shot only. I am sure they've got some kind of xray vision and can actually see clearly underground. It is apparently also a known fact that Hadedas actually don't like heights and that's why they scream like that when they fly. However, nobody will ever be able to proof me wrong. And we will never know for sure, will we now?