My dad, when the late Gracie the Great Dane mix was a pup, attacked her with his hand under the blanket, and made a fun game of it. However, in doing so, Grace, not the brightest bulb on the tree through no fault of her own, thought any lump might attack her at any time. This included lumps she created sleeping on their previously neatly made bed. Dad ruefully admitted it was his own fault that they ended up with a "90-pound moth" and they got rid of the electric blanket so she wouldn't inadvertently electrocute herself!