Robyn Francis erda at nor.com.au
Wed Jun 27 05:48:06 EDT 2007

On 27/6/07 9:41 AM, "Laurence Gaffney" <lgaffney at bigpond.com> wrote:

> As the Fruit & Nut Trees we have planted as part of the Implementation of a
> Permaculture Design start to commence producing we are finding that Rodents
> (mice/rats)  have increased their numbers significantly.
> Most of the Nuts ( particularly Macadamia & Pistachio) are taken by them
> before we get to them. Most of the fruit they seem to like too though we still
> get some.
> Vegetables also (particularly Pumpkins) are on their menu too.
> Any thoughts out their on:-
> 1.   The role of Rodents in the Permaculture System.
> 2.   Assessment of Ecological Balance.
> 3.   Mitigation. 

Hi Laurence

Commiserations... It can be tricky leaving rodents to natural predation -
while there's food and habitat they just keep breeding (breed faster than
rabbits, and have bigger litters) and can reach almost plague populations if
not checked. While I have plenty of wild predators, carpet snakes, owls,
magpies & ravens etc, I've found on occasions the rats can still get out of
hand, especially in winter when the snakes are hibernating. So I'm offering
you a last resort option for mitigation.

A few years ago I had an exponential rat population decimating the garden
and nothing seemed to make an impact so I asked my organic certification
inspector about permissible methods of controlling rats in the orchard &
garden. He recommended Racumen, but said HOW it is used is important -
mainly to ensure other mammals like bandicoots, wallabies and domestic
animals don't eat it. Racumen (available in most hardware and farm supply
stores in Australia) doesn't effect birds down the food chain, i.e. If an
owl eats a rat poisoned by it, it wont hurt the owl. However I don't know
how reptile-friendly it is. I only use it as a last resort to knock back the
population if its getting out of control, and I only use when the reptiles
are hibernating in winter. I've found an early winter hit usually suffices
to keep populations somewhat manageable.

The recommended method of laying the bait is to use some 2 litre plastic
milk bottles, cut a small rat-sized hole out on one of the sides near the
base and make sure the hole is at least a centimetre from any edges. The
bottle gets placed on its side on the ground with the hole on one of the
vertical wall sides. Then get a long metal skewer, poke it through the upper
side of the bottle at the opposite end, as far from the rat hole as
possible, then you need to stick the racumen paste sachets onto the skewer,
like a kebab (you need LONG skewers to reach to the little rat hole at the
other end to get the sachets on) then straighten the skewer and pierce
through the other side of the bottle and into the ground to peg it securely
in place. Bandicoots, bilbies and wallabies cant get to the bait in the
bottle and skewering the sachets means the rats cant drag them out for other
mammals to find. It was also recommended to check and replace eaten sachets
daily for around 7-10 days.


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