How are animals at circuses trained to do cruel tricks?

they are treated in a bad bad bad way, if you can just take a look before a circus begins from a month, you could see the sadness covering there faces, i don't think know circuses need animals anymore, if they want animals to be in their shows then let them exprience their own talent, don't force them to act like humans. because they are in this world for a reason and we are as well. so everyone should live the way god created for. They shouldn't be seen by kids in this form because kids will think that if this animal can do this then unfotunetely mine can! i hope i added information to your ideas becease i know that everyone of us has his or her own point of veiw so this is mine and im not forcing you to agree on.