In the present study, imidacloprid and lambada-cyhalothrin insecticides were evaluated on second instar larvae of Musca domestica including mortality percentage, biological parameters, and histological effects under laboratory conditions. Five different concentrations (4, 2, 1, 0.5 and 0.25%) were used. The mortality data was recorded after 1,2,3,4, and 5 days post-treatment. The highest mortality was induced by imidacloprid and lambada-cyhalothrin (100.0 and 96.6%) after 5 days post-treatment at 4% concentration, respectively. Lethal concentrations (LC₅₀) values in baits were: imidacloprid (0.13%) and lambada-cyhalothrin (0.30%). All concentrations of tested insecticides prolonged the duration of larval and pupal. Also, caused a reduction in the percentage of pupation and adult emergence compared to control. Pupal weight was also, significantly reduced. In general, fecundity decreased with the high concentration of insecticides. Insecticides caused histopathological and cytotoxic changes in the midgut of larvae. The two previous insecticides lambda Cyhalothrin and imidacloprid were also used against Rattus norvegicus males under laboratory conditions with different three concentrations (10, 5 and 0.30%) and (10, 5 and 0.13%) respectively. For two tested insecticides, the percentage of mortality reached 20 and 40%, respectively at 10% while these percentages were (10 and 30%) at 5% concentration, respectively. Also, 10% concentration had a great effect on the levels of AST, ALT, ALP, Urea and Creatine in the rat's blood. Histological tests were also conducted at a concentration of 5% on the stomach, liver and heart, it was found that some clear histological changes appeared as a result of treatment with these insecticides. Data suggested that imidacloprid and lambada- cyhalothrin can be used to help to control and eradicate Musca domestica and Rattus norvegicus especially imidacloprid insecticide had the highest effect in general on two tested public health pests.