Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes COVID-19, is thought to have originated in bats, but how it jumped hosts to infect humans is unclear, as is the potential for the virus to infect other animal species. Researchers from The Pirbright Institute have identified key differences in SARS-CoV-2 that may be responsible for the jump from bats to humans, as well as establishing which animals have cellular receptors that allow the virus to enter most effectively.