All three well understood the danger of their position.

Would the bears, after they had satisfied their hunger, go off and leave the ravine?
No.

The cave, which had been noticed, was their lair, beyond a doubt.

Even if they should enter it, what certainty was there that they would not rush out upon the boys as they were clambering down?
If so, they would easily overcome the latter among the loose rocks and bushes.

One or all would fall a sacrifice should they attempt to descend.