Need help sexing month old chicks

[ChickenTendies]

So I recently got 3 new chicks and need some help sexing them. They're a little over a month old and mixed breed. I think the dark red one might be a roo because his comb is bigger than the others, but I've heard pullets tend to grow in their tails faster. Not sure if it's true, but I'm really hoping all three of them are pullets. I'm pretty confident the black one is a pullet and don't really know about the lighter red one.

 

[Ilovemychicks08]

I think chicken pictured in picture one/two and chicken pictured in picture 6/7 are cockerels

 

[ChickenTendies]

I think chicken pictured in picture one/two and chicken pictured in picture 6/7 are cockerels

Thx!

 

[MamaPoult]

Blacky is pullet other two are cockerels

 

[fluffycrow]

The only one who might be a pullet is the dark coloured one

 

[ChickenTendies]

Blacky is pullet other two are cockerels

Exactly what I was thinking!

 

[NatJ]

I've heard pullets tend to grow in their tails faster. Not sure if it's true

For most purebred or mixed breed chicks, it is not true enough to be very useful when sexing.

For feather-sexable chicks, from a pairing of a fast-feathering male and a slow-feathering female, then yes the pullets do grow their tails faster than the cockerels (along with growing their wing feathers faster and all their other feathers faster as well.) It is possible to have a backyard mix that has those traits, but it is not particularly common.