I am a weirdo I guess. I've always been pretty successful in sexing my chicks by their personality at just a couple days old. I hatched out some Silkies in a small incubator and as day old chicks, the little girls would gladly hop into my hand and followed each other around. The little boy (1) ran around like something was after him all the time. He hated being handled. I had the same experience with a young rooster that was hatched out by one of my hens last year. He was the only rooster out of 5 chicks. He was just freaky acting and as he got older, it just got worse. My husband was convinced it was a hen because he scratched around with the hens and even clucked but he was wild when it came to me entering the coop. Since mine are mixed breeds, it's harder to identify specific characteristics that are common in pure breeds. I have teased my husband about it a lot since he's obviously grown into a rather handsome young rooster and for all of his freaky behavior that first year, he's become one of the biggest pets and likes to be hand fed now.