We have a wooden play pen we used when Matilda was little. I would use it to pop her in her rocker & be protected from the dogs if I wanted to make dinner or something while she was awake & happy. I also used it for when I wanted to go to the toilet LOL... We used it with Matilda for protection from the dogs & just so she could roll around in peace with her toys. She started going in it from 8 weeks and would sometimes be in her rocker in it. When she started commando crawling it became a life saver for me. With her at 4.5 months and me trying to do anything was very hard because all she wanted to do was explore. So I could set up toys & quilts and she would explore the play pen. I didn't leave her in it all the time, but it was great for being able to get some things done around the house & not have to worry about what she was getting into. When she started pulling herself up on things at 6 months we had to limit time in there because of the bruising (her pulling herself up on the sides & then falling over). But we used it until she was around 11 months when she started picking it up & carrying it to where she wanted to go