I really want to name my chicks! They are nine weeks old. Some people have told me the combs will be darker of they are roosters. Ive noticed that a few are way more agressive than others but. ...Any other ways to tell?
It really depends on what breed of chicken you have. There are different ways of sexing for each different breed.
e.g. feather colour.
But it would be very helpful if you could post a picture.
Aggressiveness doesn't necessarily point towards a rooster - a few of my hens will bite and peck too.
Roosters will grow combs faster than hens, though. So you can look at the combs.