Is it possible to feather/wing sex 2.5 week old chick?

[FrostRanger]

Would you say it's possible to hurt a chick if you don't know what you're doing?

Absolutely. If you don't know what you're doing you can kill or injure the chick

 

[MrsEarthern]

Would you say it's possible to hurt a chick if you don't know what you're doing?

It's possible to hurt them even if you DO know what you're doing. It involves applying pressure to force their reproductive organs slightly outside of the body; essentially causing a partial prolapse.

Despite someone saying that you can't vent sex older than 3-4 weeks, I have found that around 3-4 months old, the birds will lay or squat for me. With one hand on the back and the other moving tail feathers/ butt fluff, you can get a good look at the vent. Around this age for the early-laying breeds, they start flexing their vents. The muscle does a "flex-relax-pucker-relax-flex" movement, and I can now reliably sex them that way.