In Buddhism, there's a common practice that almost all Mahayana followers know i.e. "liberating animals". Some text books use "freeing animals". The word "animals" actually refer to "any animals" and "living creatures". Cause in Buddhism, every animal and every human is called "sentient being". The word "sentient beings" doesn't cover up such small aspect. It has a wider meaning. It refers to all beings in all dharma realms, all worlds.