We have seen a few different bird animations like this bird clock and this hero section bird animation, this latest one is from Claudia and is a button animation that changes a button to a flock of birds on click, and on hover a few birds fly out from the button. It can work really well if you have a magic or birds related site.
If you are having trouble with the pen, try the archived copy on GitHub
Button to Birds Code Snippet
See the Pen #04animation: send button transforms into birds by Claudia (@eyesight) on CodePen.default