Hi Debbie,
 
Try cutting some wire screening and duct taping it to the openings under
your dryer.  Is the ENTIRE bottom of the dryer open - or just some
openings?  Also most appliances have balancing legs that are adjustable,
try lowering them as much as possible, and placing a thick enough piece
of plywood or several pieces of cut-to-fit wood underneath that will block
their access.  We have to do this under one of our dressers to keep them
out of the drawers in it.
 
Also try sliding a piece of cut-to-fit lumber on its side between your
refrigerator and the wall.  It should block any access down low where they
can get in under the cupboard.  We had to do this behind our entertainment
center as they could get under there and we couldn't get to them when we
wanted to.
 
Just keep working at it - eventually they (and then you) will find all
those tricky spots and you will be able to breathe a little easier!
 
Karla
Meep and Daisy
[Posted in FML issue 2626]