Direwolves were the main problem of merchants that traveled between the Eastern Empire and the kingdoms around the Forest of Jura. The Empire will only take action if the wolves encroach their grain fields, a vital lifeline for the Empire. After many failures, the Direwolves have learned to avoid the fields, and remain to target the smaller-scale merchants.
The wolves did not require food to survive. Their sustenance lay in the world's magicules. By attacking stronger monsters or slaughtering droves of humans, they can evolve into calamity-level creatures, although none of these options was feasible for them. The Forest of Jura was bountiful of magic and had no monsters strong enough to threaten the wolves. However, Veldora's overwhelming magical force prevented them from entering.
When Veldora disappeared, the wolves attacked the goblins in hopes to secure a foothold in the forest. This was quickly thwarted when Rimuru aided the goblins. After their alpha was killed, the direwolves pledged their allegiance to Rimuru.
Each wolf was the equivalent of a C-ranked monster, strong enough to maul unaware adventurers. However, when lead by a capable alpha, their threat is increased. The entire pack would act as a single mind, and their ranks raised to a B.