Dick - just my .02, ferrets bad idea, I'd go for a dog; terrier type or
a cat.  To many chemicals (fertilizers, bug killers, weed killers) in a
greenhouse for a ferret is one.  You can't leave them unattended - to many
places for them to get out - greenhouses are not ferret proofed by far.  If
he thinks he can just let them out - no way.  I've never heard of a farm
mouser ferret that just hangs around the barn (or greenhouse) like a barn
cat - not even in the U.K.  If you hear different I'd say its they're an
exception and not a likely indication of success.  Last but least, you'd
probably have to go through any number of ferrets to find one with suitable
hunting skill - these farmer types aren't usually too kind to animals that
don't live up to expectations - what happens to the first couple that don't
hunt?  I've seen a lot of greenhouses with cats actually - though they may
poop in the all the abundant dirt I think if they had access to the outside
at all times they'd probably choose the outdoors.
 
Mary
 
"Animals are not brethren, they are not underlings; they are other
 nations, caught with ourselves in the net of life and time,"
  Henry Beston
[Posted in FML issue 3357]