Pending demons?
Bardeelus and Erdeta were well aware that in order to lure those remaining monsters, they just had to sit tight in one place. Those monsters were destructive, but they also were undoubtedly vengeful.
They were conscious enough to understand that their siblings got killed. Their depth of perception was scary, but at least in this case it would work out for the best, because Bardeelus and Erdeta wouldn't have to chase these worms all across the forest in order to get a shot at killing them!
They waited for a few minutes, right in between the carcasses of these worms, and as the fires died out, they heard something familiar. Trees were getting ripped apart again, which was a great hint that the rest of the worms were coming.
Bardeelus waited until the sound of their approach became unbearable, and then shouted. "Up up, now!"