the second day demonstrating the efficacy of the rodenticide of this invention table i shows the results obtained by varying the weight add on of nylon 6 12 on the zinc phosphide as well as the weight zinc phosphide added to the epa placebo mortality is reported in number of rats killed per number of rats tested and also is reported in percent of rats killed bait acceptance is reported in accordance with the formula given at the end of the table table i______________________________________encapsulated zinc phosphide zn sub 3 p sub 2 as rodenticidechoice tests domestic rats add on of mortality baitnylon 6 12 of rats acceptance______________________________________1 zn sub 3 p sub 2 in epa vs epa placebounencapsulated 5 10 50 32 18 20 90 263 5 9 10 90 345 20 20 100 4410 9 10 90 12mean ofencapsulateddata 56 60 93 312 zn sub 3 p sub 2 in epa vs epa placebounencapsulated 3 10 30 32 5 5 100 22 33 5 5 5 100 615 5 5 100 59mean ofencapsulateddata 15 15 100 47______________________________________ str1 lt 30 bait avoidance gt 70 bait preference from table i it can be observed that the 93 mortality of rats due to the encapsulated 1 zinc phosphide treated bait is significantly greater than the 50 observed from the.