Missing feathers on back help!

[chickolet]

Well we have about (30) 3 week old chicks.. today I found about 6 or so that have missing feathers on the back and the appearance of slight blood??? I had 12 chicks last year and this never happened?? we are pretty new to raising babies.. i will attach a picture, any help would be appreciated.. it seems that all of them have it in the same spot, between the wings on the back..

Thanks!

 

[poodlepill]

Looks like you have a plucker in the group. 30 is alot of chicks, is your brooder big enough?

 

[chickolet]

they are in a large animal waterer like they are in tsc...