Hello. You did not submit the text that this question refers to. This makes it impossible for it to be answered. However, I will try to help you as best I can.
To answer this question you will need to read all the text it is related to. During this reading, you will need to identify an act of kindness that Doctor DoLittle performs that causes so many animals to exist in his house. This act of kindness can be rescuing injured animals, feeding hungry animals, not rejecting animals that look for him, not sending these animals away, among others. The important thing is that you find an act of kindness that results in the amount of animals that Doctor DoLittle has in his home.