Introducing cat door?

[handsome kitty]

I currently have a flimsy barrier for my window which allows my cats out into a play area but not the yard.  I purchased a cat flap, which is a piece of wood with a cat door inserted that will fill the window.  the cats are used to just going out the tunnel from the window.  Do I need to do anything w/the cat door or will they figure it out once it is in place? 

 

[jcat]

It depends on the cats. Some figure the flaps out right away, while with others you have to tie or prop the flap open or lure them through it with treats.