On Mon, 03 May 2010 18:11:14 +0100 (BST), Dave Liquorice wrote:

You have rats living under your pond. Time for bait.

A 7" dia hole is just a bit on the large size for a rat hole. It's
big for rabbit, they are normally about 4" dia. 7" is badger/fox
size...

Ah now having seen the full post, 3" *is* more rat like but still a
little large, around 2" is more the norm for a rat.

--
Cheers
Dave.