Top on brooder or no top on brooder?

[Tmmv1]

Hi
I am on making a brooder for my young chicks. But should i add a top to the brooder or no top?
Cheers

 

[Eggcessive]

In 2 weeks baby chicks can start flying up to the top of a 2 foot high brooder, so I would put a screen or some kind of top on it. I made mine out of chicken wire stapled to a square wood frame.