Resistance to Rat Poisons in Berkshire
In Pests, Rats & Mice
We have just encountered an area of resistance to the rat poisons Difenacoum and Bromadiolone at a research centre in Compton Berkshire. Although one of the larger ‘local’ pest control companies in the supposedly hot bed of resistance that is Berkshire, at PEST UK we rarely get problems. One of the reasons is that we always deal will rat problems from many angles. We don’t just throw poison at the problem, we first asses the food supply, then where the rats are living and then use poison to eliminate the problem. It is often the case that once the food supply is eliminated (bird feeding is stopped for example) the the rats move on before taking any poison. Rats also need a place to live. They will travel to a food source but only so far. They are reluctant to cross open ground. So if cover is removed and the rats have a choice of a dangerous journey (they are vulnerable in the open to predators) or feeding on rat poison then they will eat the poison. Unless the food source is addressed or made harder to get to, rats will not feed on poison or if they do they won’t consume enough (rat poison is quite mild and normally requires that rats feed daily for several days before dying, depending on how much they eat. If they are not particularly hungry they won’t feed at all or not enough). Rats are very suspicious of ‘new’ food that is presented in a way that is not ‘normal’ to them. Rat poison in a box is a new suspicious food to rats.
The picture below is a female rat killed using Brodifacoum, which at the moment is restricted to inside use but currently have no issues with resistance.