The effect of ammonium nitrate at tested concentrations 0.2, 0.8, 1.2 and 2% and the bioagent Bacillus subtilis bacteria at 0.6×10⁴, 1.3×10⁵, 2.6×10⁵ and 5.2×10⁵ spores/ml on the survival of Rattus norvegicus rats was examined. The physico-chemical parameters of water samples which exposed to the sublethal concentration of ammonium nitrate and B. subtilis and control were determined. Also, the ileum of treated rats were analyzed after a month of the experiment using the electron microscopic techniques. The outcomes demonstrated that ammonium nitrate killed 86.66% of rats at the highest concentration, 2% after 28 days of experiment. While, the lowest concentration 0.2% did not cause any mortality till the end of the experiment. B. subtilis recorded the highest pathogenic ability against rats at the concentration 5.2×10⁵ spores/ml with mortality 60% after 28 days of the experiment. But, it did not cause any death of rats at the concentration 0.6×10⁴ spores/ml during the experiment period. The exposed water to Bacillus subtilis and ammonium nitrate has been changed in physico-chemical parameters and caused ulcers and damage to the ileum of the exposed rats. So, ammonium nitrate and B. subtilis represent successful agents for control wild rats.