Why are animals used as subject of experiments?
It depends on what kind of experiments you're talking about.
Animal behavior experiments are generally done in order to
understand why they behave the way they do, and by extension to
help us understand why humans behave the way they do.
Drug trials are done on animals first in order to see if the
treatment is a) effective and b) safe. Each species has its own
metabolic quirks, so a treatment that is safe and effective in
animals MAY not be so in humans, but it's a way to identify
treatments that are at least POTENTIALLY safe and effective for
Finally, some testing is done for teaching/training purposes. A
school may have students experiment on, say, rats even though the
expected results are known, in order to train the students how to
perform experiments in which the results are NOT known.
Plus rats, mice, dogs,primates and cats all get used for
expiriments. You may think-ew mice, rats, who cares about them? BUT
THEY HAVE A LIFE TO YOU KNOW AND THEY WANT TO LIVE IT!