good luck with them. hopefully someone will chime in with more experience. i only had two females and it's been along time since i reasearched them, which was a chore to begin with. I want to say but I'm not positive that males have a spur at the base of their tail on each side. I used a fine playsand and it worked fine. they like to burrow under things more than use a hide, mine never used provided hides but would burrow under them. becare putting anything heavy that cant sink, drop on them if burrowing under it. Hreres a old link I book marked on steno's that may help.
http://forum.kingsnake.com/gecko/messages/26506.htm
good luck, cool geckos
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My posts and replies are my experiences only
1.2.15 Tokays
1.4.10 Leos(13 albino)
1.2.0 AFT's(amel male)
0.2.0 Stenodactylus Petrii(Dune Geckos)