This popular video is a great example of why cartoon-level humanization of animals doesn't really work. Yes, it looks like this clam just stuck its tongue out and licked up a bunch of salt. But clams don't have tongues. Let alone giant tongues that would take up most of the clam's body.
In reality, that's a foot.
Have you ever looked at a mollusk like a clam and wondered whether and how it moves? That foot would be how. Clams use it for digging, because they live most of their lives buried in sand and mud. It can also be used for limited movement—usually, to get back into the water and then get reburied in the sand and mud.
Business Insider interviewed a couple of marine biologists who agree that the whole "salt-licking" thing is really just a side effect of this clam sticking out it's gooey foot.
Brian Bayne, a marine researcher from the University of Sydney agreed that this clam is definitely not feeding.
"These clams live buried in mud and they get there by digging-in with a large, mobile foot (which looks convincingly like a tongue), he said. "This clam, stranded on someone's floor, is trying to dig itself back home."
To take away the sting of scientific accuracy, after the cut you will find another YouTube video in which a (happy?) clam successfully uses its foot to return to the ocean. It's pretty cool.
Thanks to Mandy J Watson for drawing my attention to the video!