Why did the cayuga join the Iroquois confederacy?

The Cayuga joined the Iroquois Confederacy in the early 16th century primarily for mutual defense and to strengthen their political and military power against rival tribes and European settlers. By allying with other tribes like the Mohawk, Oneida, Onondaga, Seneca, and later the Tuscarora, the Cayuga could enhance their influence and resources. The Confederacy offered a unified front, which promoted peace and stability in the region while allowing member tribes to share in economic and trade benefits.