(amused) "That's very smart thinking. I'm certainly lucky to have been given such a clever apprentice."

(firmly, if somewhat fearful/panicked) "Sparrowpaw, get back! Let the adults handle this!"

(at first reassuring, then quieter [hushed] and teasing) "Oh, no. Voles aren't like hedgehogs at all, don't worry. My son, however, might share a few noticeable traits with them. Mainly his prickly attitude."