well they usually use rats, bunnies, monkeys, beagles and cats for different types of testing. They have them caged up at all times never to see the light of day. Generally for rats and bunnies (usually the testers for makeup) they’ll put chemicals in their eyes, and shave a piece of fur off and put these harsh chemicals on their skin. Like in these pictures
all chained up like this
Skin irritation tests
This one is a medical testing rat ^
Cats, dogs, and monkey’s are generally used in university labs for medical research, it which they will have things shoved in their skulls for electrodes to be attached to their brains, tubes shoved down their throats etc etc
Dogs are used for cigarette testing as well (which i dont really understand cause everyone knows cigarettes harm you)
Just try your hardest not to buy things that are tested on animals because this is just wrong.