When do chicks start acting like pullets and cockerels?

[silkiechicken]

I find my hens as adults come running for food, and that my roosters are the nicest. Walk right up and pick the suckers off the floor. It all depends on the bird though so it is hard to say.

 

[Jessimom]

I have a mix of chicks. 2 four week old silkies (we hatched), 4 two week old EEs (sexed by the feed store), and a mix of 10 day old chicks (Dominique, Black Austerlop, EE, Buff Orpington etc) also sexed at the feed store. The 10 day old chicks all hover in a corner, but 2 of the older EE's constantly are "fighting"/chest bumping with one of the silkies. These 2 EE's, and 1 silkie are the first to come over toward me when I approach.

Will a bigger silkie roo chest bump with a smaller hen?

 

[Wyorp Rock]

I have a mix of chicks. 2 four week old silkies (we hatched), 4 two week old EEs (sexed by the feed store), and a mix of 10 day old chicks (Dominique, Black Austerlop, EE, Buff Orpington etc) also sexed at the feed store. The 10 day old chicks all hover in a corner, but 2 of the older EE's constantly are "fighting"/chest bumping with one of the silkies. These 2 EE's, and 1 silkie are the first to come over toward me when I approach.

Will a bigger silkie roo chest bump with a smaller hen?

Are you trying to determine if you have a cockerel based on chest bumping? In my limited experience at that age it doesn't matter what sex the chicks are, they all will chest bump. This is establishing a pecking order, they are sizing each other up. This pecking order can and most likely change as they get older and you will see the others engage in the chest bumping as well. If you are trying to determine the sex of the silkies that you hatched, you could post in the "gender" section, but it is probably too early to tell at this young age.