Suppression of food intake by house mouse (Mus musculus) following ingestion of brodifacoum-based rodenticide bait

Rodenticides are evaluated mainly with regard to mortality, with less attention to prevention of stored-commodity losses. We quantified the extent and speed of suppression of food intake in wild house mice (Mus musculus Linnaeus, 1758) after consumption of brodifacoum-based bait. We found that although there was a significant delay in mouse mortality (LT50 = 6.4 days, max. survival = 14 days), suppression of food consumption occurred sooner: time to consume 50% of the food was 2.1 days. Food consumption was continual in control mice, while treated mice increased consumption during the first 3 days and then showed a sharp decline, approaching zero consumption by the 10th day. Although practitioners may worry that extensive damage to expensive commodities (e.g., seed packages) continues long after bait consumption due to the delayed mortality associated with anticoagulants, our study demonstrates that brodifacoum bait has high potential to substantially decrease food losses (by 75%) shortly after administration.