the smallest enclosure ive kept a pair in is a 15 gal tall. i find the most activity from my satanics when i switch up the tanks or switch up who is in the tanks. im not keeping 4 in a 30 gal long, maybe 40. breeding uroplatus takes a lot of time and patience. try giving them a bigger enclosure so you can give them areas of lots of cover, then areas with just some branches/vines to give a lil more room to move around. mine absolutely love ficus trees, so if you get a bigger tank youll be able to fit some of that in there at least. this is also a species that cannot tolerate neglect, youve gotta spray them at least once a day, id say. i normally spray mine at least twice, once during the day and once shortly after lights go out (and sometimes right before i go to bed too). also, keep food readily available and let the female get fattened up. sometimes its still pretty difficult telling that your female is gravid though.