It makes sense -- a Bag of Holding can take living beings, but they still need to breathe, and the bag has limited air.

But there is a feline urge to get into spaces, and Ilphyl is also the sort who generally does feel comfortable occasionally finding somewhere slightly small and awkward, so they are indulging the cat urge.

But they stop trying and go over to look for weeds. They can't dig as well as a cat, but they can do it a bit.