Exactly. I've kept more than one cham in a HUGE cage, but they were picked carefully based on personality and what areas they tended to use, and watched constantly for stress. Free ranging multiples can work...I've done it with melleri successfully.As a general rule, only one per cage. However, depending on several factors (such as experience working with chameleons and space) you could keep more than one in a large enough enclosure. This does NOT, of course, mean 2 or more in a standard 2'x2'x4' cage because this is not enough space. You'd need enough space so that all of them can bask and eat and roam without being constantly on top of each other and then you need to have enough experience to see when it's not working for them.