We've been weighing ours since they were chicks, using a kitchen scale. A few kernels of sweet corn usually are enough to distract our birds for the few seconds it takes to register a weight. However, the last few times we've done weigh-ins, Martha, the biggest of our hens, has absolutely refused to cooperate. I think she must be sensitive about her weight or something. Hey, Martha, no sweat, girl. You're just big boned.