I have a postal scale at home and they weighed the same as they did at the vets. My babies aren't that small though. Lilly weighs 2.6 and Tucker is 3.9.
I guess I just don't want anything to be wrong with them. But, when I put the food down it is gone within about 5-10 minutes. I currently feed them three times a day.
I agree they are probably burning it all of by playing with one another