Earlier this evening I walked into the lounge to find my toddler had wiggled a felt pen into the space behind the sofa and was drawing scribbles all over the wall. I asked him what he was doing, he said drawing and I said thats a really naughty thing to do, to which his answer was but you can't see it! I said it's still naughty even if I can't see it, we only draw on paper. Got a very sheepish look. A bit of prying later and I've now been shown his whole collection - apparently he believed as long as it was out of sight it's fine, so I have an art gallery spread around my house behind curtains, cabinets and various furniture!