Hello Amy, I'm sorry but I've read and researched for 4 weeks straight about these Grey juveniles. They ABSOLUTELY need UVB light rays to make vitamin D-3 in order to absorb calcium or they will die of bone loss. Also you are wrong about UVA light rays in which it is proven scientifically to stimulate their appetites and their overall well being. The moonlite bulb is great because research shows it gives off a small amount of heat and UVA rays too. You do not need an intense heat bulb, however they do love it, because they move and gravitate to the lights when I turn them on in the AM and PM night bulb. Plus it is cool to be able to observe them hunt at night with the Moonlite bulb. I've observed without the lights, that the 67 degree temp is too cool at night and they do not move as much and tend to hunker down more to conserve energy. I'm simulating a temperate climate for them all winter long into springtime. When I'm sure there sill be no more freak frosts temps they will be set free by my backyard pond setup just like the zoo Dr. said he did with his over wintered brood of baby Greys. I am mostly going on a post on this forum recently done by a retired zoo herpetologist, whom has raised Greys indoors and out in backyard ponds. I'm sorry I can't remember his name right now. Look up his post and you will read that you CANNOT release newly morphed or the fully morphed baby frogs because the do not have enough fat stores to make it through winter hibernation , esp in the brutal WI winters we have !!! Hope this gets you to look up more in-depth research on this amazing species of arboreal north american frog. Believe me I've done intense research and still am!!! I have TWO Biological Science degrees and trust me I know how to study and research things in-depth. I love these frogs and am thrilled at how well they are thriving!!! Thanks for you input! Frog Momma out….