It seems tarantula husbandry has evolved and improved over the years. I'm trying to catch up and keep up. I've learned recently that we don't need those stupid sponges and rocks in the water dishes and that humidity and substrate dampness doesn't seem to matter in most cases as long as there is a water dish. But with over 900+ species encompassing arboreal, fossorial and terrestrial species, surely there must be some differences in how they are housed as far as humidity requirements, right? I understand the taller cages with stuff to climb on for tree dwellers, and thick substrate for burrowers to dig in, but I need some clarification on this humidity thing. I recently had a chameleon breeder at a reptile show explain to me that panther chameleons need high humidity, but they also need very good ventilation, so screen cages were essential. This guy was from South Florida and I am in the California desert. I explained that if I house the cham in a screen enclosure, all the air circulating into the cham's enclosure will have humidity in the single digits and it will also be too cool as my room temp is fairly cool most of the year in my house. I asked him: "How do I maintain high humidity if I have super dry air circulating through a screen enclosure?" It was a loaded question and I already knew the answer, but I wanted to see what he'd say. I have great success with chameleons, and tortoises too, when I keep them in closed chambers where the cool dry air can't get into their enclosures and desiccate them. When raising "arid" species of reptile, I always give them a humid hide, and it is shocking how much they use it and what an improvement in health and vigor I see. He didn't have an answer, but man you could see the wheels turning. He'd been selling baby chams and screen cages to people who live in a desert basin all day long and this never occurred to him. I wondered as I walked away if he'd keep telling people the same things. This brings me to my dilemma: I know internet care sheets are often wrong and often say the same wrong thing, but do C. versicolor need high humidity and good ventilation, or does it not matter? If I make high ventilation, there will be very low humidity. Do I want humidity, or do I want ventilation. Can't have both where I live. I've drilled lots of holes in the tops, and the substrate is damp, but now I'm worried about lack of ventilation. Here is the little guy: Here is the dram vial I have him in with a size reference: And here is the top showing the holes I drilled: I have my Psalmopoeus pulcher and irminia housed the same way and have the same concerns for them. I lightly spritz water onto the plant and sides of their enclosures daily, but is this going to make it too wet or keep it too wet? In the past I successfully raised pink toe tarantulas from tiny little babies, in those clear plastic "amac" boxes with only two tiny little holes drilled near the top. I din't use a water dish and I didn't spray the enclosure back then, but the substrate was damp. This is the only personal experience I have to draw from for arboreal species. Please share your wisdom and experience with me on this subject. I don't want to learn the hard way at the expense of my spiders.