The testicles of eight-month-old babies seem to have become smaller, which may be due to the self-healing of traffic syringomyelia, cold weather, and so on. 1. Self-healing of traffic syringomyelia: the baby may have original traffic syringomyelia, with the development of syringomyelia closure, syringomyelia self-healing and thus the testicles may feel smaller in appearance. 2. Cold weather: testicles in the scrotum, the scrotum in the high weather will be stretched out, can play the role of heat dissipation, in the cold weather will be contracted, which can play the role of warmth. Eight months baby testicles seem to become smaller, it is recommended to go to the hospital for a detailed examination to rule out pathological factors.