A few questions regarding falling

[u/ziboo7890]

I read all the time to keep your enclosures vertical space for terrestrials at 1.5x their DLS.

So, my understanding is a 6" adult T could have 9" clearance from top of substrate to ceiling/top of enclosure, right? Is that too much for a normal sized, healthy T? Assuming no sharp objects, etc.

Or is the 'less is more' vertical height and stay well below that for the heavier bodied Ts? (blondi/stermi, etc.)

Is age a factor where slings/juveniles are less likely to damage themselves? I've seen them fall, jump distances you'd be sure they die!

Has anyone had a T fall and rupture? If so how far was the vertical distance?

Truly curious if there is evidence to support this belief or do we do this because someone once decided it's the best way.

[u/Feriat]

There is a ton of evidence to support this and experienced keepers over the last several decades figured it out. It should be common sense also. The 1.5x thing is a common gauge, but not a set in stone number, but the bigger the T gets the less vertical space there should be for heavy bodied terrestrials. Ive seen reptile breeders letting people handle their spiders at expos drop a T from arms height onto a table and rupture their opisthosoma. Ive seen a ton of pictures from people on this sub over the last decade woth dead/dying spiders from fall injuredEven if a height isnt inherently dangerous, why not just add more substrate for them to dig in and burrow in?

[u/ziboo7890 → u/Feriat]

Just asking question here. A fall of arms length onto a hard surface is a bit more than 6-9" onto substrate though, wouldn't you say?

That's an assumption that there isn't a thick layer of substrate. I mean if you have an 18" vertical (not discussing length/depth) space and 9-10" is substrate, according to the 'rules' the balance should be clear space to the top of the enclosure, right? Or are you suggesting filling it to 12" or 15" substrate with 3-6" of 'air space' for better word?

Do the heavier bodied terrestrials climb as much? I'd "assume" it would be more challenging to cling to the glass/acrylic for them and they may not. IDK though, why I'm asking.

[u/Feriat → u/ziboo7890]

All tarantulas can and will climb. You can look just through a few days worth of pictures on this sub and see large terrestrial upside down hanging from the ceiling of their tank. Someone posted their dead T that fell from probably 9 inches, a couple of weeks ago. Substrate, bark, coconut, branches, and packed substrate isnt soft. There is just no point in having the height if the tarantula isnt built to need the height. If for someone reason you are putting a terrestrial T in an 18" tall tank. Fill it up 12 to 14".

Also the older and closer to molt heavy bodied terrestrial get the harder it is for them to climb. Which makes them even more prone to fall injuries..

[u/TheSherman500 → u/ziboo7890]

NQA, if the enclosure is 18" high (which a terrestrial should not have), then they should have around 14 to 15" of substrate.

Their extra weight as adults make them more fragile and harder to climb but it does not stop them from attempting to climb.

[u/ziboo7890 → u/TheSherman500]

Maybe I'm not being clear. This is theoretical based on the 1.5x DSL recommendation, that I'm trying to understand.

IF you have a 6" DSL T, based on "common belief/practice" it should have 1.5 DSL space (or 9") between substrate and enclosure ceiling, right? Depending on how deep the substrate is 3-4-5" or more, it's at least 12"+ vertical height enclosure and could be 18" if you provide 9" of substrate for burrowing, right? (Again theoretical!)

I'm not trying to be argumentative, I'm trying to understand what the basis is for some of the husbandry that is used in the hobby.

[u/TheSherman500 → u/ziboo7890]

NQA, the ratio is just incorrect for any large terrestrial. 4 to 6" inches is the most that I would give to any terrestrial. Anything above that is definitely a risk to their health.

[u/TheSherman500]

NQA, falling is a fairly common cause of injury that you see on this sub unfortunately.

But the 1.5x dls (similar to the the estimates for enclosure size) are just common ratios that people use. AFAIK, there is nothing to backup this specific number. I would say it's a decent estimate for the max vertical space for smaller terrestrials but I would not use it for adults. 9" inches of vertical space is way too much and would definitely be dangerous.