Since 2003, Ivan Baláž has been working at the Department of Ecology and Environmental Sciences, Constantine the Philosopher University in Nitra. His research activities include the study of ecology and biology of small mammals in various types of environments, focusing on: 1. monitoring of selected species in relation to the dynamics of distribution and under the influence of land use; 2. the effect of the altitude gradient on the communities and body dimensions of small mammals; 3. monitoring of Microtus arvalis populations. He is currently studying host-parasitological relations (fleas and small mammals) and has published five monographs and more than 200 scientific papers.