The ethical treatment of amimals in scientific research

I think we can do some medical research on animals, but we should let it have less pain when it doing experiment such as giving it some good condition. Also, we can try to make it happy and give it delicious food.
Some people think we are violence because we doing experiment on animals. We love animals and want to have friends with them, but i think it is hard to stop human doing this things. Human want to live which means he may kill other species to survive or get benefit from other animals. I think it is nuture selection. Besides, i think most people don't want to dead which means we are selfish. If we don't make some experiment on animal, how could we live in the earth. However, according what i said, we make experiment on animal, but we will find a better way to do that.