Wooden hive bodies, bottom boards, or entrances showing excess moisture, or there's a moisture puddle outside hive entrance; inner covers show water stains.
Bees need water to dilute honey and to air condition their hive when temperatures are too warm. Water foragers collect water and bring it back to the hive in their honey stomach. Water foragers resemble nectar foragers. Hive bees take it from them to use as needed. Ensuring bees have easy access to a fresh water source during hotter days is good bee management.
Moisture or evidence of moisture in wooden boxes, water stains on inner covers, etc. in the hive, except during a period when bees are attempting to cool their hive, is not desirable. The bees of winter clusters generate heat to keep warm, resulting in the hot air escaping the cluster and rising to a cold surface above. If droplets form and then rain back onto the bees, they may chill and die. Wet bees move more to dry off and more moisture escapes. The cycle can prove fatal for an overwintering bee colony.
Beekeepers seek to avoid water condensing at the hive top by insulating the top of their hives (termed condensing hive) or by using a ventilating top to capture the moisture and whisk it away (termed ventilating hive). Wooden hive boxes will absorb moisture, so some beekeepers use plastic hives. Insulate hives during the winter or use a rain shelter or ramada (a roofed shelter with usually open sides) to keep rain off hives. The telescoping cover is designed to deflect snow and rain from entering the hive.
The solid bottom board will sometimes have a puddle of water when the hive is not properly leveled, i.e., slightly tipped forward, either from rain or snow entering or from the accumulating moisture of the overwintering colony. Wooden hive boxes will absorb moisture. Excess moisture can sometimes be observed on the landing board or immediately outside the hive entrance.
Generally, beekeepers should seek to avoid excess moisture conditions in their hives or have a plan to deal with it overwinter and/or prepare hives during seasons of heavy rain or snow.
