Once fox and corvid numbers are under control, it’s worth using tunnel traps to reduce rats, squirrels, stoats and weasels as well, says Liam Bell

Using tunnel traps to control small predators such as stoats, weasels and rats is time-consuming, but is nevertheless important for those of us who want to try and nurture some wild stock. Foxes and crows might be at the top of the list but, once their numbers are under control, it is worthwhile doing what you can to reduce the numbers of the smaller predators too.

Tunnel traps for stoats

Stoats are major predators of eggs and chicks. We rarely see them here but they keep turning up in the traps. Which goes to show how misleading it can be to rely on sightings to gauge numbers, even when there are people on the ground whom you would normally expect to spot them.

Catching them isn’t as easy as it may seem and while baiting traps with things such as eggs can improve the success rate the real key to catching them is a well-positioned natural-looking tunnel.

Picking the best spot for your tunnels is something of an art and is one of those things that gets easier with experience. Options include gateways, gaps in hedges, siting traps alongside watercourses, building them in to stone walls and natural features such as rock piles or placing them against rabbit netting or a natural feature that will encourage them to enter the tunnel.

The tunnels need to look inviting, and the trap itself should be almost invisible. If it can be dug into the floor of the tunnel so that it is level with the ground, all the better. It isn’t always possible, especially if the tunnel is in rock pile or wall, but you might be able to place a flat stone or two either side of the trap so that there is less of a step on to the trap from the tunnel floor. My old head keeper used to insist we pulled a light covering of sieved soil over the top of each trap with a forked stick. I don’t do it much now, but I still make sure the soil either side of the trap is firm, and that there are no stones under the plate of the trap that will stop it going off.

If you do catch a stoat, try to empty its bladder on to the tunnel or trap plate (in much the same way as you would a shot rabbit). The smell might put the odd squirrel off but it will help to pull in any other stoats that are hunting the same area.

Tunnel traps

A rat caught in a Fenn trap – rats are communal and are notoriously trap-shy

Tunnel traps for rats

Rats are notoriously trap-shy and even though you might not catch that many, every one you do catch is one less you are going to have to worry about. And for anyone who doesn’t have a rodenticide certificate come July, trapping will be even more important.

I’ve tried all sorts of ways to try to make a tunnel more inviting to rats, with only limited success. They are communal animals and, once they hear the trap go off and probably the accompanying squeak from the rat the trap has caught, they tend to shy away from the tunnel. I have tried eggs and a trap at either end of a longer-than-normal tunnel. It worked but didn’t increase the catch rate by much.

A friend came across an interesting way of increasing his catch rate by accident. He had a few rats in and around his yard, set a couple of tunnels and caught the odd rat. Not many, maybe one a week or one every 10 days. His six- year-old son pushed some feathers from the plucking shed up one of the tunnels. The following morning he had caught a rat. He reset the trap and pushed the feathers back up the tunnel. His trap caught the next five nights on the trot.

I have tried it, but only when I was specifically targeting rats, and it certainly increased the catch rate. It may work for stoats and weasels as well, but would probably deter squirrels, which is why we haven’t tried it in the woods.

Tunnel traps

Grey squirrels are relatively easy to trap, and the traps don’t have to be particularly well disguised

Tunnel traps for squirrels

Grey squirrels trap quite easily and, now that we are no longer allowed to poison them with warfarin, trapping is our main form of control. We shoot a few and make a point of checking for dreys and shooting them out when we find any. This is quite effective in the younger plantations, but it is difficult in the older woods and in parkland when most of the dreys are in hollow trees where it is impossible to dislodge any squirrels that are inside.

A tunnel made from planks is usually enough if you are trapping squirrels. They don’t need a particularly well-built or disguised tunnel like stoats or rats do and they enter them quite freely, out of a combination of curiosity and a need to keep themselves hidden from potential predators.

The beauty of a trap in a wooden tunnel in parkland, especially when it is grazed for part of the year as ours is, is that they take only moments to set, and can be moved and set elsewhere when the cattle go on to the park.

Putting a few ready-made tunnels in the back of a truck, setting them for a couple of days, then moving them on again works quite well. It is a handy way of doing things if you don’t have the time to run a trapline all week.

Tunnel traps

If you are using cage traps that capture live quarry, you must carry an air pistol for humane despatch

Cage Traps

Cage traps have their place but do take more time to set. Because whatever you catch is alive, it takes longer to get round them, despatch what’s caught, rebait and reset them. Moreover, there are bound to be times when you are passing a cage trap, see that it has caught something and have to head back home because you don’t have an air pistol to shoot whatever it is at close range or a bag in which to bolt it, to despatch it.

Pre-baiting helps, especially where squirrels are concerned, but again it takes more time than setting a Fenn-type trap in a wooden tunnel. And it has to be said it is probably less effective.

Regardless of whether we lose the Fenn trap in July or not — and it is looking increasingly likely that we will — we are still going to have to trap small mammals with something. The basics will be the same we will just have to adapt our trapping styles to the new types of trap — in much the same way as the keepers of 1958 had to do when the gin trap was outlawed.