The Lost Seas
A hurrum is a fist-sized opalescent beetle often kept as a pet by wealthier families of Athas. Merchant houses nearly always have hurrums caged in their offices.
The whirring sound of a hurrum fluttering its wings carries with it psionic vibrations that make its extraordinarily soothing. Multiple hurrum of the same sex in the immediate vicinity produce jarring, atonal whirring noises; two hurrum of the opposite sex from each other will settle into a wonderful harmonic whirr.