Why some people offer animals to God as sacrifice? Does God really like’s those offerings?

Even with respect to Gods, there are three types of Gods – Sattvic, Rajasic and Tamasic. Rajasic and tamasic Gods are offered animal sacrifices and alcohol. Sattvic offerings are done to Sattvic Gods.
In general one inherits the qualities of the God whom he propitiates. So it is always advisable to propitiate Sattvic deities.