Yes. You can always provide lots of substrate to compensate for high walls. I have spiderlings in vials where the substrate fills almost 3/4 of the vial. They have a much higher tendency to burrow as spiderlings too, so they like lots of substrate.
That would work for most species but some like Avics I tend to keep different even as tiny slings. You can always give better advice the more you know.At that size id say care is fairly generic, 20 dram vial, some coco fiber , flies, pinheads or roach nymphs depending on what you've got, if it's a burrower more coco , arboreal less coco maybe a rolled up fake leaf. Feed stare at wait repeat ! Enjoy !
As both of your sling species like to burrow (at least early on) more substrate is good. Just leave some room for feeding and for the soil the T will dig out as he burrows. Like VanessaS said long moss works good for watering or just moisten the substrate some. At that size I'd cut up prey to get the correct feeding size and let it scavenge.
What? Okay, so what exactly are you asking, why people moisten the sub? Its so tiny tiny terrestrial/fossorial slings can drink. I would recommend doing it if you cant fit a dish in.Yea i did research on old world tarantula...for now i just cut my mealworm smaller pieces and drop in,some tell me not to damp the susbstrate whats the purpose for the substrate damp,is it drinking purpose?
Spiderlings need a bit higher humidity - even the ones who grow up to be drier species and especially ones like the C. darlingi.Yea i did research on old world tarantula...for now i just cut my mealworm smaller pieces and drop in,some tell me not to damp the susbstrate whats the purpose for the substrate damp,is it drinking purpose?