Rats and mice are abundant in the South this autumn after two summers where they have had access to ‘‘enormous'' amounts of food, Pest Management Association of New Zealand executive Bill Paynter says.
Cooler autumnal temperatures drive rodents indoors, seeking shelter, but there is much householders can do to help make their homes rodent-proof.
Removing vegetation which was up against your house or over hanging it, cutting it back to a metre away from the building helped prevent rats jumping on to the house, he said.
If an electrician covered exterior wiring near where it entered the house with a loose-fitting alkathene pipe, mice and rats would fall off when they tried to run over it. An annual check of air vents, repairing any broken ones, was also wise.
Mr Paynter advocates applying the ballpoint pen test to gaps around the house.
‘‘If a ballpoint pen fits, a mouse will fit. If you can slide a ballpoint pen under a door, put a bristle strip under it.''
As well as keeping the mice at bay, that helped prevent heat loss, he said.
Some other gaps, such as those around water pipes, could be filled with steel wool which cut rodents' gums if they tried to chew it.
Rats' ability to chew through ‘‘almost anything'' should not be underestimated. (Rat's teeth rate 5.5 on the Mohs scale of hardness, compared with 10 for diamonds.)
If people could hear rat activity in their ceilings, it was time to call a pest controller who would be able to advise on future prevention as well as eradication.
Using a controller who was registered with the Pest Management Association offered protection ‘‘if something goes wrong'', he said.
Winter cold meant a lower survival rate for litters, but spring was another peak time for rat and mouse populations.
RODENT PREVENTION
- Remove food scraps and water sources (leaking pipes, old tyres, pots collecting rainwater).
- Store any rubbish in containers with secure lids.
- Do not leave uneaten pet food out overnight.
- Clear overgrown parts of your section and places which might provide nesting sites.
- Bury compost in the garden.
Source: Dunedin City Council
