100% depends on the betta, so it's totally random.
Some make them ALL the time, some only make them sometimes, some just seem not to at all. It could be disappating across the tank because there is not enough stuff at the surface for him to build it against/for it to cling to, or because of the filter.
Mine always make theirs around and under the leaves of the live plants in their tanks that reach the surface.
One of my boys makes a bunch of small tiny ones (usually under the leaves at the surface) but only somtimes, the other ALWAYS has a huge one up, the only time he doesn't have a giant one is after i ruin it with a water change, but by the next morning there is always another one up to replace it lol
Last edited by peachesxo; 02-24-2012 at 06:32 PM.