The Behaviour of the House Mouse (Mus Musculus L.) in Relation to the Development of a New Control Method Using Contact Rodenticides

Abstract

Current methods for house mouse control and possible alternative strategies were reviewed. A contact rodenticide held within a tube was selected for further study. The work can be divided into four main parts:- 1. Mouse movement patterns in pens with particular reference to tubes and tunnels. 2. Possible repellency of rodenticide formulations. 3. Development of a suitable formulation. 4. Design of an applicator to ensure optimal uptake of rodenticide. Experimental simulations of house mouse infestations in food storage premises were developed and found, by comparison with large scale field trials, to be a reliable test environment for contact rodenticides. Additionally, patterns of damage in pen simulations have clarified some of the factors involved in the infestation of stored food. It was found that mice continue to enter long tubes (in excess of 500mm) throughout an extended period (weeks) whereas entry into short tubes became less frequent after an initial exploration. The provision of side apertures was shown to increase the frequency of entry into a tube. Tacky and greasy surfaces were found to be repellent, thereby excluding this type of formulation. The effect on grooming behaviour, and on consequent uptake of toxic doses, of application of formulations to various parts of the mouse's body was investigated. It was concluded that a liquid or a soft waxy formulation gave the best combination of low repellency and adequate uptake. The most effective applicator was a triangular prism with toxic formulation along its ridge and sides, placed longitudinally in a tube in such a way that a mouse must straddle it to pass through the tube and thus receive a fatal dose on its belly and flanks. This system was adapted into a contact rodenticide device now being manufactured.