Persistent rat control difficulties, that can easily be put down to rodenticide resistance, all too often result from a failure to adequately account for the scale and extent of the infestation.
All too often, baiting is confined to the areas in which rats are seen, while most infestations extend throughout the farm, and as a result only a small proportion of the rats actually visit the baiting points, then those consuming the rodenticide are replaced by others from the immediate vicinity as soon as they succumb to it.
This gives the clear impression the rodenticide is ineffective, but in reality, it means it simply isn’t being used widely enough or in sufficient quantity to do the job.
In some – thankfully still limited – parts of the country resistance is a concern, but professional control success continues to prove that the overwhelming majority of farm rat infestations can be overcome by well-managed baiting based on a good understanding of the problem.
The key to effective control, in my experience, lies in using the most palatable farm-wide rodenticide, putting it out in well-sited baiting points wherever rats are active, and topping them up frequently over an intensive treatment programme.
With large infestations and where alternative food sources are plentiful it’s particularly important to employ the best quality bait.
You should also use more than enough baiting points and site them wherever the tell-tale signs of rat activity are evident. This will almost certainly be along the outside of buildings, in recesses, at the edges of hay or straw stacks and in undergrowth between their burrows in rough ground and buildings. The bait must be available in sufficient quantity too. Bear in mind that an initial consumption of 3-4 kg/night can be expected with a reasonable-sized farm infestation – baiting points need to be checked and topped-up at least three times in the first week.
An intensive three-week round of quality baiting will always be more effective than sporadic and less well-planned treatment over an extended period, and will minimise risk to non-target species.
Rapidly eliminating the overwhelming majority of rats in this way will significantly reduce the speed and scale of any re-infestation, saving time, effort, damage and, importantly, bait use.
Here is my 12-point Farm Rat Baiting Regime:
1. Survey the whole farm visually to establish where rats are active
2. Draw a sketch map for use as a baiting plan and for reference
3. Use tracking patches of silver sand to pinpoint main areas of activity
4. Establish baiting points and mark them on the map for reference
5. Choose a top quality bait
6. Place sufficient bait in each baiting point (following recommendations)
7. Inspect and top up each point with fresh bait daily for the first week
8. Keep topping-up the bait every two or three days thereafter until all consumption ceases
9. Check for signs of activity by freshening the silver sand tracking patches
10. Clear away all bait once no further signs of activity are evident
11. Pick-up and dispose of any dead rats in accordance with legal requirements
12. Leave the bait points in place to bait again at the first signs of fresh activity.
Euan Bates is an Oswestry-based farm rodent control specialist