How much water do ants need?
Ants, as any other insects may get all their water needs trough food supply. If there is any more need than that they find other source of water. (for example ants do not react to clean, dry sugar, thay can only absorb it in water solution). Depends also on the actual ant species.
Ants are attracted to sugar and do not die from eating sugar or sweet things. Most people think sugar kills ant because they try to exterminate the ants with sugar water. The water is what kills the ants. For example, if a bowl of sugar water is left out to kill ants, the sugar attracts the ants but the water drowns the ants.