OK for medium sized snails

We were looking for something simple to keep a few snails (small quiet animals but nevertheless fascinating to observe). One can easily develop a kind of garden with a small dirt tray 4 cm deep and feeder flour and coqullles of beaten eggs. By adding lettuce leaves, sliced ​​carrots, a carpet of moss and some branches on which they can move at will just close it recreates their natural environment and they seem to like it. One small drawback: the hatch from above does not close very well (but it is true that often we leave open for our small "snails" may occasionally explore a little the outside world).
Of course, they must be cleaned daily.