A terrarium is an enclosed space that hosts its own ecosystem. Very similar to a mini greenhouse. The ecosystem consists of plants or mosses and can even include animals like frogs and geckos.
There's no need to go and buy a ready-made product. Building a terrarium is fun and easy, the design limited only by your imagination.
You can even use a lightbulb, and be as creative as "Steamed Glass" in this incredible piece of art:
Another great idea if you're short on space is to hang one from your ceiling and bring a little bit of nature into your home.
Exo Terra produce ready-made kits for kids as well as various accessories. There are a number of animals you can have:
It's a good way for children to learn about small reptiles and their relationship to nature. They'll also learn about the cycle of water in a practical way.
Yours does not need to contain animals. It can be a focussed plant vivarium where plants bring all the life. You can still decorate it according to a theme such as desert or medieval to make it into a wonderful display that will be a great conversation topic.
Desert themed cases are enclosed cactus or succulent gardens. Having them enclosed in glass gives your more flexibility in terms of sand and accessories and reduces the care further from ordinary potted cacti.
Wardian cases are older versions of the same "ecosystem in a box" idea and are lovely pieces of furniture to have in your house. They were originally used in Victorian times to protect ferns from London's air pollution and later to transport plants long distances.
One of the really great things about these little worlds is that they need very little care, because they are close to being a closed ecosystem. Minimal water (sometimes you won't need to water for up to 4 months!) and a bit of trimming and little to no fertilizer will keep most happy!