I have 7 hens. 2 of them are about 7 months and the other 5 are about 4 months old. I am a little bit concerned about the two 7 month old hens because they have yet to lay any eggs. The breeds are Astrolorpe and Americauna. I spoke to my neighbor who have raised chickens and she said, "sorry, at 7 months. You have roosters." Both of these "hens" don't crow in the morning but she said that some rooster don't crow. Is that possible? How do I check the sex of the chicken? Thanks!