Mine took 4 months or so to get in my RBTA. I helped things along by placing the RBTA where the clowns had staked out their favorite spot. Both will go in but the female sleeps in it and goes in and out all day. At first I noticed the female looking at it a lot, then getting closer, then glancing off of it and eventually it was in. The clowns were pretty young when I got them so maybe they had to mature? The male was in it a lot one day but I haven't seen him go in since. He sleeps alone at night :-(.