Volatile fatty acids (VFAs) are a group of common metabolites with a potential of universal infochemicals dedicated to transferring of information between higher organisms and bacteria either from microbiome or external environment. VFAs are common substances among various insect orders, there are numerous studies exploring their influence on the behavior of different insect species. In relation to papers published by J. E. McFarlane, we assess the effects of formic, acetic, propionic, butyric, valeric acids on spatial preference of common stored food grain products, and poultry industry pest – lesser mealworm (Alphitobius diaperinus). We present novel method of continuous, simultaneous assessment of site preference as well as travelled distance in constant-flow olfactometer. All tested VFAs except valeric had a significant repellent effect with formic acid being effective in the lowest concentration. Additionally, VFAs significantly altered distance travelled by insects. Obtained results indicate a potential role of VFAs in the olfactory guided behavior of A. diaperinus, we speculate that reaction to the presence if VFAs may deviate form specificity of species’ original habitat.