A gadfly (somes spelled as gad-fly) is someone who “irritates, torments, or worries another.” The term takes its origins a combination from the Old Norse gadd-r for spike or nail and fly, referring to the insect. This second word stems from the primary definition of the word which refers to the type of fly that bites and irritates cattle. The secondary intent of gadlfy was first recorded in 1657 by George Daniel, a poet and playwright, in Trinarchodia.
The parrots in this video seem to take great pleasure in being gadflies towards their canine playmates. The parrots stalk, cajole, and sometimes steal sticks while the dogs warily avoid the sharp peck of a beak.