Hive
Contents
Problem Definition
As is known, the hive is a community that is very complex and is influenced by both internal and external factors. Also it is said, that hive is the only working communist and feminist community in the world. Therefore,the simulation was created to examine the influence of internal and external circumstances which influence the hive and the ecosystem in which they live. Especially I mean these factors:
- Number and distance of flowers to pollinate
- Number of workers and drones in the hive
- How duration of winter affect stocks of honey and colony survival
- How number of workers affect pollination of flowers and therefore the number of flowers in neighborhood.
The goal of this hive simulation is to understand the dependencies among factors listed above.
Method
Because of hive is multiagent system, NetLogo 5.0.3. is used for this simulation. NetLogo is powerful tool and is easy to learn. But it has also disadvantages. For example low speed and performance.
Only standard NetLogo procedures and features was used, except some turtle´s shapes, which was created by author.
To understand dependencies of individual factors, lot of data is needed. The results presented in this page comes from many repetitions of simulation with many different settings of model variables.
Model
As it was said, hive is very complex community and it´s behavior is also very complicated. Therefore the model is simplified to be able get reasonable results at reasonable time. That is why only important influences was chosen for this model.
Model behavior
This model tries to imitate behavior of the hive and surrounding areas with flowers, including changing of day and night and season.
Next sub-chapters describing behavior of individual parts of the model and we can distinguish these agents:
Beehive
Beehive is a "home" of bees, including workers, drones and queen. Also bee´s larvae (eggs in model)growing in the beehive. In the beehive are situated provisions of honey which is consumed by bees, when they are hungry. Bees are hidden here during the night and winter.
Beehive is randomly situated on the grass in the model or is in the middle of the grass(depending on settings).
Workers
Workers are female bees which are responsible for pollinating the flowers and collecting the nectar. They flies random direction in the morning to find flowers. If they find them, they pollinate it and collect nectar. Every worker can collect only 3 mg (milligrams) from each flower in a row, then she moves and looking for another flower. When worker has 30 mg of nectar, then she returns to the beehive. If the worker is very close to beehive and found the flower, then she tells other workers in the beehive direction of the flower. If worker didn't find anything, then it returns to the beehive.
Every worker consumes honey in the beehive. Worker consumes 4.5 mg of honey (nectar) a day (in the night and winter consumes a half). At the beginning of the simulation the value of energy is set for every worker to her maximum level. Maximum level of energy is defined as random-normal distribution, mean 22, standard deviation 2.5. This value describes how long can worker life without food. If variable energy = 0, then worker dies. If the value of energy is less than 5, than worker moves back to beehive for honey and if there is enough honey, then sets energy to the maximum energy.
Workers has also age, which is set at the beginning of the simulation. The value of age is defined for each worker as random number from 0 to 40. If age is > 50 in the summer or > 180 in the winter, worker dies.
Drones
Drones are male bees which are responsible for fertilization of the queen´s eggs. They flies random direction a when they meet queen, they fertilize her and than dies. If they don´t meet her, they flies back to the beehive and than flies random direction out of the beehive again.
In case of honey consumption it is the same as workers except their max energy value, which is defined as random normal distribution, mean 18, sd 2.5 Just as workers, drones has age set and defined same as workers, except winter. This is because drones are expelled from beehive and the community at the beginning of the winter.
