The cells that make up i insect nestslike bees and wasps, present perfectly regular shapes: they are all identical and of hexagonal configuration. This feature is not the result of the case, but represents an optimal geometric strategy. Generally, the nests of the wasps are spherical in shape, divided into structures called favi And built using chewed and saliva wooden pasta, which gives them a consistency and an appearance similar to those of the paper.
The main difference between a hive and a vessel nest is given by the material with which they are made: while the hives are made of wax and have the typical shape of the inverted glass, the Vespai have spherical shape and are made with a material reminiscent of the cardboard.
How a vespe nest is made
Although the wasps are social insects, like the bees that build their nest with wax, they use a material similar to cardboardobtained by mixing wooden fibers with saliva and resin. Depending on the species of wasps, The nests can be in protected and not very disturbed placestherefore some of the most common places include: attics and gutters, cavities, branches and bushes, but also garden furniture and barbecue.
Taking into consideration, for example, the nest of the Vespa Velutina (also known as the Asian Calabrone or Calabrone with yellow legs), an invasive species originally from Southeast Asia and introduced in Europe in 2004, a complex structure can be observed: the outermost layer of the nest consists of numerous superimposed “sheets” , which form a thick and resistant barrier, capable of protecting them both from predators and from temperature variations, thus acting as a real insulating. The internal cells are organized in called structures faviarranged on several levels and connected together by means of small pillars, also made with the same paper material.
How they learned the wasps to build such a complex nest
The structure of the nests is extremely complex and contains one optimal geometric strategythe result of aneffective natural organization. Mathematics that apply was not what we learn about school desks, but is based on essential principles for their survival. Scientific studies have shown that the wasps have the ability to recognize and respond to basic numerical conceptshow to count objects or orient themselves in space. These are innate skills, which allow them to make decisions based on the quantity and adapt to the challenges of their environment. In the case of the nest cells, The choice of hexagonal form is not the result of the case. While not having an abstract awareness of what an hexagon is, evolution has selected this solution because represents the most efficient configuration in terms of energy saving and offspring protection.
Because bees and wasps use the hexagonal form
The hexagon has a unique property: It is the shape that allows you to cover the maximum space without leaving empty. Even squares and triangles can obtain the same result, but the hexagon has a fundamental advantage: allows you to enclose the same area with a lower perimeter. Let’s take a practical example. Suppose we have to cover 1 m² of surface:
- If we used a square, each side would measure 1 m, with a total perimeter of 4 m
- If, on the other hand, we used a hexagon, each side would be about 0.62 m long, and the total perimeter would be about 3.72 m, lower than that of the square
This means that, to build the nest, wasps or bees they use less material and energy, maximizing the efficiency of the structure. In addition, the favi are arranged symmetrically, stacked and connected to each other by strategic pillars. At the basis of this construction there is an essential concept, which we also use in our daily life: thebalancewhich depends on the center of gravity. In the nest, all plans are disk -shaped, a configuration that allows you to distribute the weight uniformly. In addition, the strategic arrangement of the columns gives greater stability to the entire structure. This organization offers two great advantages:
- An optimal weight distribution, which protects the nest from external factors such as wind and rain, avoiding the collapse of the structure
- Greater resistance and flexibility, allowing to expand the colony by adding new cells without compromising the stability of the nest
As they can combine large cells and small cells without interrupting the scheme
The arrangement of the cells presents a geometric challenge linked to taxing: not all cells have the same size. The smaller ones host the workers’ wasps, while the larger ones are intended for males and future queens. There is then the problem of having to combine hexagons of different sizes without creating empty spaces. To solve it, the wasps adopt an ingenious precaution: when necessary, they build cell couples with slightly different shapesfor example one with five sides and the other with seven. In this way, The gap between the cells of different sizes is filled, while maintaining the regular scheme.
This stratagem guarantees that each pair of cells has the same number of open sides – that is, not in contact with other cells – compared to a couple of traditional hexagons. The model, therefore, does not stop but gets on again to accommodate larger cells. If, on the other hand, you simply try to insert wider hexagons, the structure would lose its geometric consistency and empty spaces could form, compromising the efficiency of the nursery.
How much does a Vespa live? The life cycle
What allows the wasps to build such a complex structure is theirs extraordinary social organizationknown as eusociality. At the head of the colony there is the queen Which, after being fertilized and surviving winter, begins the construction of the primary nest alone, of a size similar to a tennis ball. Here it lays the first eggs, from which the sterile workers. These have a single task: complete the mother’s work and expand the nest.
At this point, the colony can follow two strategies: to build a larger secondary nest or expand the existing one. In both cases, the queen will dedicate itself exclusively to the deposition of the eggs, while the workers will deal with the growth of the structure. In September the first appear male and the New fertile queenswhich will be coupled to found new colonies. With the arrival of the cold, the nest begins to empty: the young queens seek a refuge for the winter, while the old queen, the workers and males die. The cycle ends with the arrival of the frost and resumes every springthus guaranteeing the survival of the species.
