My players were fighting their way through a swamp and they were fighting some will-o-the-wispswill-o-wisps.
The fighter had a fun idea to put one of them inside the bag of holding. Since it was at the end of the encounter, I thought it would be cool to let them pocket the wisp.
I'd like to know if, by RAW, it would be possible to do that (I already let them do that either way). Since the wisp can't be grappled, I don't know if such action would be possible by using force, but the way the player worded the action made me imagine they'd use the bag like a net to capture the wisp.
Also, would the wisp just pass through the bag to get out or wait until there was an opening?