HINDU -
Majority of Indian including Nepalese kill animals to sanctify weddings, new homes or religious festivals. Upon purchasing a new car or truck, the owner sometimes splashes its exterior with fresh animal blood, to ensure the vehicle doesn't crash due to satanic spirit. Many times, puja is merely symbolic - an offering of rice, butter, non-pasteurised milk, and flowers etc. When an animal is to be sacrificed, however, it should be an uncastrated male which is killed, apparently as a display of life's potency.