I have a hive that I am trying to save. It started off as a very strong one and when I began having SHB issues about a month ago I saw that the population was suddenly very low and appeared to be queenless. I was forced to decrease it's size to help allow for less space that the bees would need to patrol and it is now down to one deep brood box with a screened bottom board with a tray filled with oil. Believing that it had lost it's queen (not able to find her) I removed the frames that looked spoiled and replaced them with a frame of honey, two frames that were partially filled with brood, and a few undrawn foundations in hopes they would raise another queen. They have been limping along, appeared to be building a little comb, but always seemed to be there at dusk guarding their entrance. Then yesterday when straining the oil from the trap I saw quite a few dead SHB larvae in the oil but very few if any adults. This evening I noticed that the front of the box now appears to be covered with bees and some are lined up down the side around the edge where the bottom board meets the box. The temp here is 89 with a humidity of 23%. My hubsand wondered if these bees are robber bees and I wondered if they may all be new ones indicating that the population has grown. Wouldn't robber bees go home at night, or would they stay at a different hive? In the morning I plan on going out there to see what is happening inside. It may be a lost cause to try and save it so late in the year, but it made me question where robber bees go at night. Does anyone know?