marcia told me a similar story about the squirrels in her yard. they were driving her husband up the wall because they kept pulling up patches of sod all over the place. well ... it turned out that they were just digging up things they'd buried. they remembered all the locations and weren't letting a little thing like new sod get in their way.
anyhoooo ... it only happened during that first season. once the squirrels had found all their previously buried treasure the digging stopped because they buried their new "jewels" someplace easier to get to.
make your squirrels pay for their share of the sod. they'll be more careful. or ... just patch it this year and wait patiently for next. :wink: