One of the ten tested beehives was selected to demonstrate the
performance of the proposed detection system under the longterm
field test. Fig. 12 shows the daily frequencies of honey bees’
incoming and outgoing activities during the experiment. Although
the frequency of honey bees’ incoming activities is similar to the
frequency of honey bees’ outgoing activities, the latter is usually
higher than the former. An inspection of the recorded data in
Fig. 12 indicates that the daily counting difference between the
incoming and outgoing activities was lesser than 300 counts/day.
The recordings in other beehives looked very similar. The reason
behind the frequency of honey bees’ outgoing activities is usually
higher than that of incoming activities may include the attack of
wild animals, natural death, expulsion by other bees, and getting
lost with every pollen-finding expedition (Morse and Flottum,
1997).