Two early signs of dehydration are thirst and dark-coloured urine. This is the body's way of trying to increase water intake and decrease water loss. Other symptoms may include: 1  dizziness or light-headedness. 2  headache. 3  tiredness. 4  dry mouth, lips and eyes. 5  passing small amounts of urine infrequently (less than three or four times a day).
Diurnality is a form of plant or animal behavior characterized by activity during the day, with a period of sleeping, or other inactivity, at night. The common adjective used for daytime activity is diurnal. The timing of activity by an animal depends on a variety of environmental factors such as the temperature, the ability to gather food by sight, the risk of predation, and the time of year.
Depending upon your location on the Earth you may experience Diurnal, Semidiurnal or Mixed Semidiurnal tidal cycles. Click the image for a larger view. If the Earth were a perfect sphere without large continents, all areas on the planet would experience two equally proportioned high and low tides every lunar day.