Citronella essential oil offers a short-term solution for repelling rats, although it is not able to keep them away from your home forever. This is true of all rat repellents, as they are only designed to scare rather than eliminate them. Rodents can also become accustomed to the scents around them, so if the nest is a particularly large one, then using citronella may not be enough to keep them away for long. If you are experiencing an infestation of rats then we advise that you contact a professional pest control company who will be able to provide a suitable, long-term solution for the problem.