Mealies won't eat through a leo's stomach. If their teeth don't kill them, the stomach acid will do it quite quickly. Many breeders in the leo forum will attest to the healthiness of mealworms as a staple diet. There have been several debates (almost as many as 'is sand safe as a substrate') and the results have been 50:50 for crickets vs. mealworms as a staple food. Of course variety is always a good idea.
Feel free to drop by that forum and ask some questions. The people there are very knowledgeable.
A single leo can be housed comfortably in a 10 gallon. Leo's only grow to 8-10" long, and a 10 gallon is 12x20. Unless it's a large male, a 10 gal should be fine. 20 would be nice and of course extra room is always nice, but 10 is fine.
>>i agree that the leopard gecko is the best one for her, but i believe it should have a minimum 20 long... as would all the species listed in the previous post. unless you are talking about trully miniscule animals that don't get much over maybe 3 inches, nothin is gonna go in a ten gallon, (at least that i can think of). also i would recomend against the mealworms as they have been known to occasionally eat their way out of lizards. so unless you chop of their heads prior to feeding a would abstain from feeding those, additionally crickets provide a much better nutritional value. i think she would be more than pleased with a leopard, and once you get it and put it in the ten gallon, you will agree that an adult needs a larger tank.
>>-jake

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Blaine
0.0.1 High Yellow Juvenile Leo (Echo)