World Day for Laboratory Animals is marked annually on the 24th of April to raise awareness about experimenting on animals. Animal models have been used for scientific purposes, such as helping us understand cell mechanisms, complex biological functions and in finding new cures for diseases. Due to anatomical and physiological similarities between humans and animals, especially mammals, potential medications, vaccines and therapies are first investigated on animal (and non-animal) models. Clearly, not all results conducted on animals can be directly applied to humans; rather, they help us understand crucial processes and decide whether it is safe to move on to the next level. It is almost impossible to imagine biomedical research being run without animal models as they are crucial for fundamental discoveries – from ancient dissections to contemporary gene editing technology.