I have 4 WC Syno. Multis. They have been established in their current tank for about 2 months. They are with 5 Calvus, 12 Gibbs and a few bristlenose. Their tankmates are all 2 -4 inch max. and they are much larger then anything they swim with. My question is, what would cause them to hide 99% of the time? It has been awhile since I have had multies but my last group of 6 were all over the tank most of the time. Daytime, nighttime didn't matter, but these 4 are extremely skittish and any sign of movement they try to get deeper into cover that they are already in. Even at night with all the lights out they rarely come out. I find myself digging around the tank every few days just to find them cause I am worried they are not eating or might be stuck. The tank is 100g, has average cover and is in a low traffic area of the house. Is it just these four personality? Or do I need a couple more possibly to make them feel like more of a school? Any suggestions would be appreciated.