Wasps are normal in the warm season and we encounter them every day when we are outdoors. Their coexistence and behavior are fascinating and amazing at the same time and so we ask many questions about their flight behavior, nest building, and flight times. But also about aspects of daily life such as: Do wasps actually have to pee or poop?
Wasps have an active metabolism and a digestive tract that they use to convert nutrients into energy and waste. These unusable by-products are disposed of as a pulpy yellowish substance from a cesspool in the abdomen.
However, wasps are not random excrementeers, but rather handle their excretions very consciously. In this article, we describe when and where they drop their waste products, what it can look like, and why it is not harmful to us.
Why do wasps poop and urinate?
Every living being has a metabolism that ensures nutrients are absorbed and processed. This creates energy and enables the organism to grow and build up. When converting these raw materials, there are always waste products that cannot be recycled.
These must be removed from the body, otherwise, they would build up and cause further problems. In addition, the excrement contains harmful substances that would be dangerous to the body in the long term.
The exact process of this differs greatly in the animal kingdom and has not been researched in detail for many insects. This also applies to the wasps, whose excretions are rarely part of larger studies.
However, there is a basic understanding, transferable processes in related species (such as bees) and observed behaviors that show how wasps get rid of their waste products.
This is how wasps produce feces and urine
The content and form of the excretions are primarily determined by the structure of the digestive organs and how they work.
Wasps have a digestive tract that breaks down nutrients (especially short-chain carbohydrates – like ‘sugar’) and ensures that they are absorbed into the hemolymph (the wasp blood). From there it is transported to the necessary tissue (such as the flight muscles) in the body and converted into energy.
The waste products from the organs return to the hind digestive system via the same route. In addition, wasps have so-called Malpighian tubules – fine tubes that absorb the nitrogenous waste products from the hemolymph and transport them to the digestive tract.
Like all insects, wasps do not separate their metabolic products (urine) from their digestive products (excrement/feces) and release them through a single opening (cloaca) in the abdomen after the substances have been mixed in the back of the digestive system.
Wasp excrement and wasp urine: Appearance.
Wasps do not have kidneys, as the main component of their excretion is urea which is not toxic at all (while uric acid – which is also found in humans – has to be greatly diluted in order not to have a toxic effect).
The urea can thus be excreted without an increased need for water. As a result, the consistency of the excretions is mostly pulpy, but at least viscous.
Only in exceptional cases with increased liquid absorption (and separation) does the release change to a very liquid substance.
The color of the excretions strongly depends on the food consumed. It varies between yellow and light brown tones and can also remain whitish (since this is the color of urea).
The size of the excrement is related to the size of the producing wasp. It can be said that the width of the shedding is up to 1/6 the width of the wasp’s abdomen. For a “normal” yellow jacket this is 0.6-0.9 mm (0.025-0.035 in) and for a hornet 0.7-1.1 mm (0.027 – 0.04 in). Correspondingly increased dimensions apply for the 30-50% larger queens.
The length of the detached stool is limited to the length of the digestive tract, although the maximum is never actually reached. Excrement with a length of 60% of the abdomen or 30% of the body length (approx. 0.5-0.7 cm / 0.2 – 0.3 in) is possible.
A potential consistency and color can be seen well in this beautiful video. In addition, the “pumping process” for pressing out the chair is clearly visible.
When do wasps poop?
The frequency of a wasp’s bowel movement is directly related to its metabolic rate. This varies over the year and reaches its greatest activity in midsummer.
This is due, on the one hand, to the higher temperature (since wasps are cold-blooded and many metabolic processes run faster at higher temperatures) and, on the other hand, to the fundamentally increased consumption due to the maximum activity when building nests and supplying the state.
The food ingested is also a factor that affects the metabolism. Nectar and other simple sources of carbohydrates are easy to digest and, to a large extent, usable. This does not apply to vegetable components of food that cannot be used in the short digestive tract.
This dietary fiber is only absorbed to a limited extent by wasps and so there is no “permanent flow”.
Feces are deposited several times a day and, in addition to cleaning, also have an aerodynamic function.
Regular lightening reduces the flight weight and thus increases the effectiveness when flying. This in turn saves energy and enables the wasp to transport more food into the nest.
Wasps have a distinct diurnal rhythm and are not particularly active at night. As a result, they pass most of their stool during the day.
(This only applies to a limited extent to the largest wasp species – the hornet – which is also active during the dark. Here, the frequency is more evenly distributed over the entire day.)
Where do wasps poop?
Wasps are clean creatures and have a great interest in avoiding all dangers for the nest. This includes in particular the introduction of pests, fungi, and bacteria.
Wasps defecate outside the nest.
Therefore, they always do their business outdoors. It is possible to dispose of the excrement both in flight and after landing. The relief in the air is probably the more common variant, as wasps can stay cleaner here and minimize contact with the excretions.
Wasps that are inside the nest and have to defecate move to the nest entrance and do their business there, or take a disposal flight. There are no reports about the wasp queen, but it is likely that she will not leave the nest and that the cleaning will be done by the workers.
Do wasp larvae and wasp pupae also defecate?
In addition to the queen, the offspring do not leave the nest in any phase of development (egg, larva, pupae). However, wasps have no metabolic outlet during this time and therefore do not deposit any feces.
Only adult wasps poop.
While the egg and pupae only have a limited metabolism, the larvae are very active in absorbing nutrients. However, a large amount of recycling is achieved here and only a few waste products accumulate.
Are wasp droppings harmful or corrosive?
The excreted substances in the wasps’ stool have no caustic or toxic effects. The urea is absolutely non-toxic and is even used in the manufacture of cosmetics.
The solid part of the excrement does not contain any questionable components either. The manure is filled with indigestible substances that have not been chemically processed.
Wasp droppings are harmless.
This means that there is no damage to furniture or clothing. Any remaining stains can simply be wiped off or washed.
Wasp droppings in winter
Unlike bees, wasps do not retreat to their nest and survive the winter there. After the new wasp queens have flown out, they go to winter quarters, where they hibernate in winter until spring. During this time they have no metabolism.
The rest of the state dies in the following months and does not survive the winter. So there is no nest that fills up with excrement over the winter (bees hold out until spring and only then go on an extensive disposal flight ).
Wasp droppings: Not important for us
The impact of wasp droppings on our lives is marginal. The small quantities and the wide distribution make contact with us very unlikely. And even then, there are no disadvantages to fear.
The only nuisance that could occur is pollution in the immediate vicinity of the nest. This can lead to an increased release so that the excrement can be determined.
