Do Anroids Dream?

I found it really odd that the people in "Do Anroids Dream?" can control their moods by this device. They wake up in the morning and turn the dial to control how they will feel the whole day. It doesn't seem human to me that you can control your emotions by a machine. I don't understand why they have that mood device. I also found it interesting that there are so many odd animals in this story. For example, Rick Deckard has a sheep and then gets an electric sheep because his first one passes away. Also, there is an ostrich that comes into play. I don't understand the meaning of all of these odd animals that Rick Deckard obtains. It is weird that the electric sheep is on top of Rick's roof. Also they talk about a donkey and a toad. I just don't get the meaning of all these diverse creatures.