Tips on controlling rats under your macadamia trees
Removal of food. This is the first step to controlling rats under your macadamia trees.
Use a $5 plastic rake to remove all unharvested nuts at the end of the season. Burn or dump them. Leave no food for rats to be attracted to.
In autumn when the blackbirds and thrushes have left their nests, remove their old nests. Otherwise rats will move in.
Ensure your compost heap does not attract rats.
Control Options. Once you've taken the above steps, you have a number of options.
Poisoning. We use Racumin paste in sachets. The sachets are like teabags. Skewer the sachets on a piece of sharpened no.8 wire inserted through the middle of a 100mm Novaflow pipe or similar. Any pipe will do. It should be big enough to fit your hand in, but not much bigger. It should be about 400mm long. Place the pipe and bait on the ground where the rats are busy, or up on a branch. Bait stations should be not closer than 20m and not further than 50m apart. Check and replace eaten baits every 7-10 days. The big advantage of poisoning is that it works when done properly. But it costs money, the rats die an unpleasant death, they smell if they die where you dont want them to, and the risk of accidentally poisoning other animals has to be well managed.
Live Capture traps. These are good around the house or buildings where you dont want poison. Set them where you can see and check them daily. They have to be positioned where Tibbles and Rover cannot reach them, or they will wreck your trap trying to get to the rat. The advantages are that the smell of decaying rats is avoided, you have no poison worries, and once you've spent the $20 initially, there are no ongoing costs. But you have to dispose of the live rat with the cute eyes (usually by drowning), birds get caught, and coverage of a big area is not a realistic option.
Snap traps. The old fashioned snap trap is OK inside a building, but not outside where birds will get killed.
D-Rat traps. These traps are more effective than simple snap traps. Check them out on https://envirotools.co.nz/products/d-rat