The message
from "cpemma" contains these words:

Dave Liquorice wrote:
On Sat, 17 May 2003 22:04:43 +0100, ned wrote:

)snipt)
An adult mouse will get through a 1/2" dia hole no problem, 3/8" will
slow it down but will still get through...

A pest-control expert on TV recently said (of mice getting into houses) if a
biro would go through a gap, a mouse could.

I've seen a mouse disappear into the much-smaller-than-a-biro crack
between a skirting board and a wooden floorboard.... (under extreme
duress; three dogs and two cats were pursuing it round our sitting room
at the time).

Janet.