Rats and the placement of rodenticide baits for their eradication on indoor livestock farms

The frequency and distribution of specific structural farm elements in relation to the occurrence of rats was investigated on 24 German livestock farms, 18 in Lower Saxony and 6 in the Münsterland area. Using the interactive control programme BayTool® we also examined whether the allocation of baitingpoints to these elements would result in complete rat eradication. Standardized rat control measures were applied with baiting-points allocated to six specific structural elements on these farms, and the feeding activity of rats was recorded for each of these elements and their position. Rat activity mainly occurred at five specific structural elements. Farms with rat infestations held a higher number of the element ‘old materials’ than rat-free farms. The allocation of rodenticide baiting-points to five specific structural elements is a precondition for complete rat eradication. Most rat feeding activity was observed at baiting-points allocated to ‘old materials’, ‘stacks’ (of construction materials), and ‘livestock’. Rat feeding activity was predominantly located outdoors at ‘old materials’ and ‘stacks’. The stringent allocation of baiting-points to six specific structural elements is a reliable means of rat eradication and rat monitoring on livestock farms. As most rat activity on livestock farms is expected outdoors a rodenticide must be chosen that only poses low secondary poisoning hazards