Rodents

We are often asked for advice on the control of rodents but you may prefer to employ a professional exterminator. These are listed in the Yellow Pages under Pest Control.

Rats and mice are a nuisance. They are known to damage food and property and are responsible for spreading disease either:

Directly – by contaminating food and belongings with urine and droppings (eg Salmonellosis and Leptospirosis)
Indirectly – by their fleas and mites (eg the plague and typhus)

They are mostly nocturnal animals and are rarely seen during the day. Droppings, gnawings, burrows or tracks will alert you to their presence.

Mice tend to live inside where it is warm and dry and rarely stray more than a few metres from their nest. They prefer to feed on grains, cereals and other dry goods.

Rats generally nest outside under buildings, in piles of debris or in overgrown parts of the section. They range further than mice and will feed on almost anything including meat, fish and rubbish.

Both creatures are incredibly agile and can climb most vertical surfaces, leap across wide spaces, swim very well and squeeze through very small gaps – just 12mm wide.

Rodent control

Always wear rubber gloves when disposing of dead rodents whether poisoned or killed in a trap. Dispose of their bodies in an appropriate manner.

Rodents can usually be controlled by baiting or trapping. However, to effectively control rodent problems you must also deprive them of:

Entry

Ensure your home is rodent proof
Seal holes around pipes into buildings
Seal gaps under and around doors Repair holes in wall cladding
Repair broken windows
Cover air vents with fine wire mesh

Food and water

Ensure your property is clean and hygienic
Remove food scraps
Remove water sources such as leaking pipes, old tyres, pots that collect rainwater
Remove rubbish immediately or store in containers with secure lids
Never leave uneaten pet food out overnight

A home

Ensure your property is clear of potential nesting sites
Discard unused newspapers and other junk or store it neatly at least half a metre off the ground
Bury compost in the garden
Clear overgrown parts of your section

Bait

Poisoned bait is available from garden or hardware shops. Follow all instructions and warnings and always wash your hands thoroughly after handling it.

Tips to remember when using bait:

Place the bait where the rodents are active, such as in the ceiling cavity, under the floor, in the garage...
Always put bait out of reach of children and pets.
Make a bait box - put the bait under an upside down (ice cream) container with small holes cut in opposite sides for the rodents to gain entry, and a weight on top to stop it blowing away or being knocked over. A length of 80mm or 100mm drainpipe also makes a simple bait box for outside.
Leave bait down for at least two weeks after the rodents seem to be gone
For mice, which only nibble at food, put down several lots of bait close together to make sure they eat enough of it.

Trapping

If you don’t want to use poison, traps work well with mice. Rats are a little more cunning and tend to avoid traps.

Traps are best located in areas such as burrow entrances or along their track ways. You need to check them daily and reset those that have been successful.

Last reviewed: 19 Mar 2009 12:42pm