glass window safety

Would a wendy house with glass windows be safe as an interior cage for two indoor buns in a large kitchen? They have the run of the kitchen 20' by 20' for one hour in the morning and then all evening. I was going to put shelves up at different heights in the wendy house but am just dubious about the glass windows. Thank you.

http://www.gardenbuildingsdirect.co.uk/Wooden-Playhouses/Mad-Dash-Childs-Log-Cabin-Playhouse#none

It seems to be styrene glazing not glass - so it is acrylic - it may be an idea to cover it with mesh or take one out and mesh it for more ventilation?