I have heard of some using tiny zip ties and writing on them. I have kicked around using them and may go for it because you can put info on the tie and as the chick grows change out the zip tie and the info. The info I would put on the zip ties is 1) my guess as to gender, 2) pen they are out of, 3) hen they are out of, 4) date of hatch so it would look something like this - p,1,3,6/19 p stands for pullet, 1 is the pen #, 3 is the hen #, and the last is june 19th. If I go to this method I will band each of my birds with a number and their pen will have a number painted on it. So the roo will just have the number of the pen, the hens will have the pen # and their own number such as one two or three. The hardest part will be keeping up with which hen laid what eventually. Right now I only have 3 hens per pen and they each lay a slightly different egg, so they are prett easy to identify. As my pens get bigger and if I add another roo I will need to revamp my recording system, but it seems like it may work for now.
Lanae