When the water reaches the building that they were in, the water won't be that strong anymore.
At least even if it floods, they don't have to worry about the building being destroyed because of the rapid and powerful flow of water that would be coming.
Luciel just sat up on the bed but didn't bother going near the window to see what was going on.
But with the sound of incoming water, the rats seemed to be more agitated as they started making noises and running around the building again.
Luciel could clearly hear the sounds of mice going around. It was obvious that they were all avoiding the oncoming flood, so they were trying to go somewhere higher.
Maybe those rats moved this morning because they already knew that a flood was coming, so they moved somewhere else first.
Treyton and the others were watching what would happen later, but Luciel's curiosity was already satisfied, so he didn't bother with it any longer.