Last year that is all I used for my brooder....
used it on chickens, guineas and even ducks for a shorter period...
worked great for me and I was able to put netting on top to prevent the little guys from
trying to fly out....I also used a heat lamp, switching mid season to the red heat lamp.
I had the vinyl pad and put puppy pads atop that with a layer of shavings...made clean up great
and the little ones weren't slipping around due to that vinyl pad.
I have 2 week old chickens in it now....guineas are hatching out tonight and have them in a
large tote box with center part of the lid cut out and wire put in place. The tote is clear and makes
it also easy to see the keets inside.
I don't know what kind of heater the last person is talking about but other than a light being on
24/7, the heat lamp works great. . . wouldn't the heater have to be on 24/7 as well?
( I too used playpens for my puppies in past years)