Sub adult in Leachies is sort of unclear as they get so big. Giving an SVL (snout to vent lenght) will help folks determine the size of the gek. I have found that you generally have better success with single animals, especially new ones in a smaller rather than larger cage. They find their food more readily and generally feel secure, plus it is a lot easier to keep an eye on them for food consumption and feces analysis. You can easily put an adult GT Leach in a 10 gallon tank in the short term, such as for quarenteen.
I have an adult C. paulsoni in a 10 gal tank, and she does fine. Yes a bigger cage would be better but space for her in a larger cage is not currently available. A snake analogy so to speak.
The other mind set you have to get into with stickey foot gex is going VERTICAL. Think emerald tree boa. You can put gex in a small foot-print cage (floor area) but tall, as long as you fill the open space with branches to climb on. I run trios of R. ciliatus and R. auriculatus in the equivalent of 30 long aquariums set upright, on their ends, and there is plenty of space.
The other thing a gek needs is a hide box, either a half flower pot or a plastic container with a moist soil in the bottom, same thing as for a snake shed box. Leachies will eat pinkies and/or fuzzies depending on size. They are sight feeders so if using FT then you may need to aggrevate them by poking the mouse into their snout to take the FT. With gex movement (not smell) is food, watch those fingers a Leach can do damage, think carpet python, I have been bitten by both, I would rather the python...
I am sure others can advise on final housing and pair housing. My post was just for dealing with the animals short term from a snake keepers point of view.
Good luck they are SUPER animals, you will not be dissappointed.
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