animal randomization

[Michael Sylvester]

how necessary is it to randomly select animals for the control and
experimental groups in animal studies?
so you got 100 rats,50 to go to the E group and 50 to go to the
C group,can randomization really equalize for the two conditions?
It appears that there is already a stability factor,since some of those
animals may be bred from the same strain or litter?

Send me something.

Michael Sylvester
Daytona Beach,Florida