People often ask me "Dr Bellend, how do you keep pesky squirrels off your nuts?". Well, here's the answer..
We had about 3 persistent little buggers that would take turns on the bird table and scoff everything without the
 birds getting a chance. I even purchased a squirrel feeder which I attached to a tree, but they still weren't
satisfied!  After various attempts with mechanical devices I concluded that the pesky critters were just too agile
and brainy to be beaten by such devices. So, not wanting to be outwitted by a rodent I turned to electricity.....

I ran a wire from my greenhouse underground and up to the bird table. I mounted the bird's nut feeders on
insulators from electric fence posts and livened them up with a borrowed electric fence controller. There are
2 methods the squirrels use to get on the table, up the post and jumping from the nearby bush, so I protected
the post with some wire also. I also ran an earthed wire round the rim of the table to ensure a good connection
on the little bugger's feet. The electric fencer produces pulses of about 7Kv every second and while not dangerous,
it will give a painful shock. Some come back for 2 or 3 attempts before they give up. The shock causes them to
take flight (literally) and they run off up the garden wondering what hit them. Most satisfying. Of course I don't need
to tell fellow geeks that the birds are not affected by this because they don't present a path to earth, similar to when
they sit on power lines.

Warning: The Squirrelzap uses a harmless low-power farmer's electric fence controller. Dr Bellend does not
accept responsibility for any loss or injury incurred by persons attempting to reproduce this system in any way.
(This includes barbecued squirrels and people).                             
Our innocent looking bird table.
The electric fence controller hiding in the shed.
Electrified nuts!
Anti-climb protection!
How to turn a normal unexciting squirrel.....
.......into a flying squirrel.
Video of a squirrel getting 13 Amps at U Tube: