Bearded Dragons are popular exotic pets, most commonly Pogona vitticeps, the Inland or Central Bearded Dragon. They are a popular species among children, because of their friendly and calm nature, along with the relative ease of caring for them. Most Bearded Dragons in captivity have broad triangular heads and flattened bodies, with adults reaching approximately 16 to 22 inches (410 to 560 mm) from head to tail and weighing 350 to 600 grams (10 to 20 oz). Many Bearded Dragons have native habitats that are dry and sparsely vegetated, so food may often be difficult to find in the wild. As a result, Bearded Dragons are omnivorous, capable of subsisting on a wide variety of food sources. A typical diet for captive Bearded Dragons includes leafy greens and vegetables, avoiding lettuce and any other vegetable composed mostly of water, and regular meals of feeder insects, with crickets being their main insect matter, or 'morio' worms (giant mealworms). Their stomachs are large enough to accommodate large quantities of food. Young Bearded Dragons do not eat as much vegetation as their adult counterparts. As a Bearded Dragon ages it may be persuaded to eat less animal matter and more plants, maybe levelling off at around an 80% plant and 20% animal diet. Popular feeder insects include Superworms, crickets, roaches, locusts, silkworms, hornworms and butter worms. The mealworm has a fairly hard chitin and is generally low in the "meat to chitin" ratio, as well as having poor calcium/phosphorus content, making it far less nutritious than other feeder insects. Waxworms and superworms can be given as a treat, but sparingly as in most cases as they are extremely fatty, and in some cases very addictive, although they can be useful in building up an undernourished animal. The rule of thumb on feeder insects is that the food must not be larger than the space between the animal's eyes; feeding something larger could make it hard for the animal to swallow the food and can lead to fatal impaction. A significant portion of the Bearded Dragon's diet consists of leafy greens. Dragons enjoy many types of readily available greens, including: collard greens, spring greens, escarole, turnip greens, mustard greens, dandelion greens, parsley, and carrot tops. It is also recommended that this portion of the animal's diet be supplemented with a variety of finely diced fruits and vegetables. Feeding a mixture of these plants ensures a wider variety of nutrients, and variations in texture to aid digestion. Other greens or vegetables and fruit that an animal may eat include grapes, strawberries, raspberries, bananas, papayas, melons, apples, peaches, pears, orange-fleshed squashes, mangoes, pattypan squash, pumpkins, green beans, peas, maize (corn), broccoli, carrots or their tops, beetroot, nasturtium, alfalfa (lucerne), celery, rosemary, oregano, basil, hibiscus, pansies, carnations and rose petals.