Yes. A red-eyed tree frog can live with another red-eyed tree frog, and these frogs are often kept in small groups rather than alone. That answer comes with conditions that matter more than the simple yes: the frogs must be close in size, the enclosure must give each animal its own vertical territory, and feeding must be supervised closely enough that no individual quietly loses condition while its tankmates thrive.
Why Groups Suit This Frog
In the wild, red-eyed tree frogs gather on vegetation overhanging pools, and several animals may spend the day asleep on neighbouring leaves. They are not territorial in the way many geckos or monitors are, and a well-matched companion rarely causes the chronic stress seen in solitary species forced to share. By day your frogs will mostly ignore each other, each pressed flat against the underside of a broad leaf; activity begins after lights-out, when the group wakes, hunts and calls.
Similar size is the first filter. A much smaller frog competing beside larger, bolder animals eats less, gets displaced from the best perches and can be injured during an over-enthusiastic feeding lunge aimed at an insect near it. Match animals by body length and build, and be especially careful about adding a young frog to established adults.
Setting Up a Shared Canopy
Think in height and leaves rather than floor area. A tall vivarium with large-leaved plants, cork branches at several levels and multiple hides lets each frog choose a separate daytime sleeping site, which prevents the low-level jostling that happens when two animals want the same leaf. Keep humidity high with regular misting and a shallow, clean water bowl for soaking, and make sure ventilation stops the air turning stagnant in that damp warmth.
House any new frog separately first and observe it eating and behaving normally before it joins the resident. That pause protects the established frog from anything the newcomer might be carrying, and it gives you a baseline for how the new animal looks and feeds when it has the place to itself.
Feeding a Pair Without Favourites
Competition in this species is quiet rather than violent, which makes it easy to miss. Offer insects in more than one spot, tong-feed the shyer frog directly if it hangs back, and count what each animal actually takes over several evenings. Weigh or at least photograph both frogs regularly from above; a frog whose back is narrowing while its partner stays plump is losing the contest, however peaceful the tank looks.
Separate the pair for feeding or permanently if one frog stops eating, loses weight, spends the day exposed instead of tucked onto a leaf, or shows wounds after nighttime activity. A frog that has been ill should also recover alone, where its appetite can be measured honestly.
Living With the Group Day to Day
Once settled, a pair or trio is genuinely rewarding: calling, hunting and colour changes happen on the group's own nocturnal rhythm, and the frogs tend to use the whole planted height of the enclosure. Keep a simple note of who ate, who shed and who called, because in a group those details blur together unless somebody writes them down. KinsLe Family Sharing helps here by keeping each frog's profile and care notes open to everyone in the household, so the person misting tonight sees what the person feeding last night recorded.