yemen/veiled chameleons arnt a mean species, or non of the ones ive delt with have been anyway.
the veiled get to around 18-24" when fully grown (including tail) for a single animal the minimum size viv i would recommend would be 24*18*12. this gives the animal plenty of floor space aswell as a good depth for climbing.
for two or more animals (ideal would be say 1 male 2 female) i would recommend a 36*36*15 tank, this would easily house 3 adult specimens and give them room to get away from each other should they wish to do so.
you should have a heat mat on the bottom of the tank on the INSIDE of the tank, covered with a slate. then place your braches/plants etc inside, over head you want AT LEAST a 5% ubv tube, a 7/8% would be better.this will need to be protected. and should be on for approx 12 hours a day. then depending on the depth of the tank, you will also want one or two over head spots, i find for a 36*36 tank, 2 60w blubs work well. i recommend fixing these up on a frame work outside the tank to that there is no way the animals can come into contact with them, but are still getting sufficient heat from them.
but this is just my 20p worth
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