Rat control, cheap and simple

Everyone hates rats. When you keep chickens, they seem to turn up more often, so you need to know how to control rats safely and cheaply. This post will tell you how.

Recently I had the pleasure of visiting the most gorgeous lifestyle block owned by a clever and resourceful couple. They are doing forest restoration and pest control in an adjacent patch of beautiful kahikatea forest.

I noticed that they were using the cleverest and cheapest little bait station for rats that I've ever seen. They told me they'd invented them and that they work really, really well.

Firstly, you need a tunnel, because rats love going through tunnels and to keep non-target creatures away from the bait. Here they have just used icecream containers with rat-sized holes cut in two opposite sides. Note that the holes (doorways) are cut slightly above ground level to keep out puddles when it rains.

Note they've pinned down the icecream container with bent wire.

Home-made wooden tunnels, and plastic piping work well as tunnels too. Place tunnels next to fencelines, buildings or something else if possible - rats are more likely to choose these than tunnels on open ground.

Slightly to the side of the tunnel is poison bait on a nail. The nail is simply driven up through the middle of the bottom of the icecream container. Then, to keep the bait dry above any puddles that do get in, they have used a small bit of narrow plastic tubing over the nail (I think a small hunk of rubber would work well too). The bait goes over top of that.

Bait often comes with a hole in it for this purpose, so the rats have to keep coming back to nibble it. With loose baits the rats take the whole bait away and hoard it. Once I bought bait without a hole in it and tried to force it onto a nail, and it just crumbled away - it was such a waste of money.

What kind of bait?
A common type is made by Pestoff. Rats love it (presumably because of the smell and flavour) and it contains the poison brodifacoum, an anti-coagulant. One ravenous nibble of it is deadly to rats. However if cats or dogs eat poisoned rats, they can get secondary poisoning. They won't die the first time - they'd have to eat a lot of them - and the vet can administer something to counteract it.

Alternatively you can use Ditrac or Contrac bait, which doesn't have the secondary poisoning effect.

The bait is available from places like RD1, Farmlands and Bunnings. Prices can be lower online, however. I've been pleased with the service from this online bait and trap shop.

What about traps?
Traps are good too. They pose no toxicity problem and you get the satisfaction of a rat corpse. The most successful type seems to be the Victor trap, baited with peanut butter. Traps, too, should be in tunnels.

Why everyone should kill rats
Aside from spreading disease and scaring chickens (have you heard the alarm call that chooks make when they see rats?), rats are bad news for nesting birds. One of this country's top bird scientists once told me that 75% of all nesting attempts of NZ forest birds end in predation, mostly by rats. They are sneaky, silent killers that are quietly decimating our wildlife.

The way I see it, we brought the rodents here, so it's our responsibility to sort this problem out!