God asks for more animals to die

Numbers 6:9 says, “And if any man die very suddenly by him, and he hath defiled the head of his consecration; then he shall shave his head in the day of his cleansing, on the seventh day shall he shave it.

6:10 And on the eighth day he shall bring two turtles, or two young pigeons, to the priest, to the door of the tabernacle of the congregation:

6:11 And the priest shall offer the one for a sin offering, and the other for a burnt offering, and make an atonement for him, for that he sinned by the dead, and shall hallow his head that same day.

6:12 And he shall consecrate unto the LORD the days of his separation, and shall bring a lamb of the first year for a trespass offering: but the days that were before shall be lost, because his separation was defiled.”  Why does god need these animals to die?  I think it would be nicer to just have the person give something up?  Why does the animal have to die.  Remember, god is the one making the rules.  He could have had the sin offering be giving up wealth or standing on ones head for a full day.  Why does god like to choose the killing of animals?