The working thesis is about to know if the insecticide product used in gas form for pest controlling lets some type of solid rest above the surfaces. Samples of mammals skin, feathers and butterflies have been used in order to compare those being treated with others without insecticide treatment. The comparison has been carried out by electronic microscope. Apparently, the results can not prove that the product we used contains any type of solid components that would rest on the surface of the observed samples.