The wandering nature of these creatures has been attributed to their apparent predilection for hunting prey of high intelligence. From their diet of Nature's intelligentsia, they receive nutrients to aid their own development, and it so often follows that fledglings are often vapid and dull. Some strains, however, such as the tiny bug, never leave the larval stage, and so die as poor of wit as they were when they were born.
I should think you know by now that arrows, shot, and the like are a prized commodity in these parts, eh? Most of them, you see, must be imported from other lands! We've none but ourselves to blame, mind you. If only there were a few more people here with the skill to craft them... Aye, that's why you'll be going to the bazaar for your munitions. Bring some scales or fangs and you'll get what you need.