I don't know, you should ask a GERBIL book!! :P
You should wait until their eyes are open. Or when the mother will let you near them.
Newborn gerbils weigh only 2.5-3.3 grams, and are about 3 centimeters long. That's about the size of a penny!
Most babies take 3 months to grow out of newborn clothes, some babies are larger than others and grow out of newborn clothes sooner than others but 3 months is average.
gerbils get to be about 4 inches long with 3 inch talls so about 7 inches total
They vary, most gerbils grow to 4-6 inches (10-15 cm) long [not including the tail; up to 12 inches including the tail]. Great Gerbils, the largest gerbils, grow up to 8 inches (20 cm) long [not including tail; up to 16 inches including the tail].
Gerbils can grow to be about four inches long without the tail. Depending on the tail length, they can grow to be about 6 to 10 inches long.
At day seventeen newborn gerbils will open up their eyes, they will have most of their fur as well then. At this point their will be very nervous because it's an entirely different world so be patient and gentle with handling them. Good luck with your gerbils :D. Wonderful gallery of a gerbil litter from birth to three years of age: http://www.egerbil.com/gerbil_birth_to_three_years_of_age
3-6weeks
It usually takes four hours to grow one year.
A newborn hamster will not go half a day without eating.
2 days
Same as a hamster or mouse