My two older girls took almost a week to open the flap. It's a screened
flap attached to my sliding screen door to my deck. Eventually when they
saw me sitting out on the deck, having a snack, they pushed their way
through. The kitten I got at 8 weeks old took about 2 or 3 days to get the
hang of it. She watched the older ones go in and out and she went right
ahead first using her paw to push out the door. I then showed her to just
use her head to push her way out. I think a screen may be easier to use
than a plastic flap.

My cats do not go off the deck which has a 6 foot high fence around it.

Barb