The present invention provides a warning light which is placed inside a water feeder. The warning light comprises a waterproof casing having a light, a switch, a battery and a counterweight inside. Accordingly, when there is water in the water feeder, the warning light will via the counterweight float on the water inside the water feeder. Or the warning light will lie down on the bottom of the water feeder. The present invention also discloses that the warning light will be placed in positions of different angular via the amount of the water inside the water feeder so that the switch inside the warning light can be switched to open/close anticipatively. Further, the feeder can realize that there is water in the water feeder or not.本發明是提供一種飲水警示燈，是在給水器中置放入一飲水警示燈，該飲水警示燈係由一防水外殼於內設有一燈、角度開關、電池、重錘體；依此，當給水器中有飲用水時，則該飲水警示燈為會藉由重錘體而半浮於飲用水其水面上，另當給水器中無飲用水時，則該飲水警示燈為會倒臥於給水器底部；本發明即是利用該飲用水之有無，而讓飲水警示燈產生不同角度的擺放，俾使飲水警示燈其內之角度開關達到預期的開/關該燈，進而便於飼育者得知給水器中是否有無飲用水。
