Much of the research in rodenticides today is directed along the lines of the 

 anti -coagulants. Used dry, in a cereal mixture such as cornmeal, or with a little 

 oil added to prevent dusting, insects and mold may attack the finished product. Most 

 insecticides and mold inhibitors leave objectionable tastes that cause marked reduction 

 in acceptance, so investigations are being made of candidate materials to overcome 

 this problem. Although warfarin is exposed in such dilute mixtures that primary 

 poisoning by accident would require the ingestion of a huge quantity of bait, that 

 occasionally has happened. Also, a few cases of secondary poisoning have been 

 reported, due to pets feeding daily on dead or dying rats or mice poisoned with 

 warfarin. Efforts should be made, then, to recover rodent carcasses whenever 

 possible. As with other poisons, the majority of complaints of warfarin failure can 

 be ascribed to faulty technique in exposure or failure to maintain a fresh, acceptable 

 bait supply until the entire rat colony has been eliminated. Since some rats may not 

 start feeding on the bait until it has been exposed for some time, or feeding may be 

 intermittant, two or three weeks may be necessary to produce results; a mouse colony 

 may require as long as thirty days to complete their removal. 



No mention has been made of desirable bait materials, since local availability 

 and cost are determining factors. Then too, acceptance is so widely varied, even on 

 adjacent premises, that selection must be left to the judgment of the operator. Often 

 only trial and error will provide the correct answer, pre-baiting being the most useful 

 technique. Here, again, knowledge of the characteristics of the various poisons is 

 important, as many of the bait formulations are based on the specific chemical that is 

 used. Weather conditions should be considered before exposure. Above all, hazards 

 to other animals must receive top attention; using materials and employing techniques 

 best calculated to destroy rodents without attracting or being easily available to others. 



The destruction of rats and mice is one of the important steps in attaining 

 permanent rodent control. Poisons represent the most efficient and useful tools in 

 accomplishing this end. Full advantage should be taken of the particular characteristics 

 of each of the rodenticides, selecting those most likely to produce the desired results 

 under the specific conditions where they are being used. 



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