If you get NO feelings like this, we will know something else entirely. We shouldn't be hasty, but we WILL act. They inhabit a wholly different set of spheres, which occasionally overlap ours at places. Because the magicians who try this act on the assumption that these beings are naturally evil, they rarely provide basic nourishment for them, let alone treat them with any sort of respect. How a loose Critter behaves depends on what version of our life-forms it corresponds to.
Critters eat energy.
Energy is produced by a great many means, but the most easily available is the energy produced by emotions. When intelligent Critters act to reproduce the emotional energy they found before, they generally have no clue that emotional energy comes from intelligent beings. Some of them, but not most of them, still wouldn't care. Imagine having only sprouting potatoes to eat, and being hungry eough to eat all of the potato. Such a ball of energy may well be the first nonpoisonous food the Critter has had in months.