I’ve noticed this phrase a lot online recently. I haven’t heard it much in real life, with it being an American-English term, but it certainly seems to have cropped up a lot lately.
If you’re not familiar with it, it means to accept that you’ve been wrong or beaten, particularly if you’ve made an embarrassing error. The phrase was first recorded in the 1870s in the United States as to eat boiled crow, presumably because crow (presumably) doesn’t taste so pleasant.
It’s interesting to look at other similar phrases: to eat humble pie, to eat your words, to eat your hat. Why all the eating? I think it might be related to taking a remark back. Often when we use the phrases when someone has said something to regret. So when they have to atone for their error they have to reverse the action. Rather than opening your mouth and letting words out, you’re putting words back in. Or substitutes for words, like crows, or humble pies.
I still think there’s more to using crows in this phrase than their not tasting nice though. There are plenty of other things that probably don’t taste nice. Mice. Badgers. Bats. Eating bat: I think that could take off.