Swarm Summoning Cheese

You amplify the scent of the cheese, summoning 1d20×the spell level rats. They are passive to all, but if you attack them(aka make sudden movements while wading in them or just killing them) or the cheese wielder, they attack you, dealing 1d4 × the rats in damage. Every round the current cheese wielder must make a dexterity check(dc 15) to save the cheese from the rats. When they fail, the rats take the cheese and leave.