get rid of them.
put them out of their reach
spray them with a citrus smelling spray.
spray them with feliway

It might help to give the cats something they prefer, something like a
coarse grass: wheat, oats, and other coarse grains sprout quickly and
are very popular with house bound cats.  These do require pots and
soil, but you can use popcorn sprouts when they are several inches
long.  Popcorn is easily obtained at any grocery store and can be
sprouted between (vertical) layers of damp paper towels in any
container - give enough daylight to ensure a good green color.

--
T.E.D. (tdavis@gearbox.maem.umr.edu) DO NOT send attachments: messages with attachments are deleted at the server.

Put them in a hydro culture, then they play with the stones instead ;-)

Carola