Bait additives as a means of improving acceptance by rodents1

There is a general desire by those formulating rodent baits to improve them to achieve better rodent control. Various bait additives are currently in use while others have been evaluated without significant benefit. Some food or taste preferences are innate while other specific food preferences of rodents are learned during early experiences in life. Sugar (sweet items) and vegetable oils and animal fats are the most universally effective additives for cereal baits to improve acceptance and palatability for the three major species of commensal rodents. Salt, monosodium glutamate, and a wide array of natural, semi-natural, and synthetic flavors/aromas as bait enhancers have been explored as gustatory (taste) and olfactory (odor) additives. Their influence on rodents seeking out the bait and on bait acceptance are varied and inconsistent. Flavor additives to baits have often decreased rather than increased consumption.