We are brand new to chickens this year. They free range during the day and then at night we have a chicken area in our barn where we keep the larger chickens (3 months old) in and there is a pen inside this area for our little chicks (5-6 weeks old). Last night something got in and didnt get the bigger chickens but instead got into the pen and killed 3 of the babies :-(
What would skip open area chickens to break into an enclosed pen?

You can see to the right the pen the little chicks are in...

I am so upset! i spent this afternoon blocking every gap I could find but..i'm so afraid i'm going to get home to more carnage (i work 3rd shift) i realize i was lucky to only loose a few but its horrible to see them all torn up.
What would skip open area chickens to break into an enclosed pen?
You can see to the right the pen the little chicks are in...
I am so upset! i spent this afternoon blocking every gap I could find but..i'm so afraid i'm going to get home to more carnage (i work 3rd shift) i realize i was lucky to only loose a few but its horrible to see them all torn up.