The primary wildlife reservoirs for Trypanosoma cruzi in the United States include opossums , raccoons , armadillos , squirrels , woodrats , and mice . Opossums are particularly important as reservoirs , because the parasite can complete its life cycle in the anal glands of this animal without having to re @-@ enter the insect vector . Recorded prevalence of the disease in opossums in the U.S. range from 8 @.@ 3 % to 37 @.@ 5 % .