We can encounter bats everywhere. In caves, forests, cities and yes, even in our houses, the attics or cellars of buildings. But this should not worry us, especially because the legends regarding bats are merely legends. Instead, we should be happy because of the presence of bats. We should be extremely happy, because the activity and presence of bats is highly beneficial for us, mankind.

Since their appearance on the stage of evolution, bats began their thorough and high quality work: they visit millions of specimens of hundreds of plant species, thus spreading the pollen and seeds of these plants to new areas. Other bats, due to their immense appetite, control the number and size of insect populations, among which there are several pest insects, mosquitoes, moths, beetles and others. Without bats it is very likely that the modern world we live in, would look very much differently. Without the more than 1,300 species (which is an approximate number of bat species worldwide), probably even we, humans, would have followed another path, to discover a world quite different from what we see now.

Arborele de cacao și avocado sunt doar 2 dintre cele 450 de specii de plante, care beneficiează de activitatea liliecilor - A kakaófa és az avokádó csupán kettő a kb. 450 gazdaságilag fontos nővényfaj közül, melyek a denevérek segítségével is terjednek. - The cocoa tree and the avocado are just two of the more than 450 economically important plant species, that rely on bats (Chocolate photo: Олена Полункіна/Wikipedia, bat photo: Szilárd Bücs, avocado photo: Wikipedia)

The most obvious benefit arising from the presence of bats is that they eat enormous quantities of insects. Even if we are unaware of this, bats are indispensable in many areas of our lives, for example in agriculture and forestry. One of the most famous, but especially tasty examples is chocolate. Yes, bats, or rather bats in tropical areas, helps us to obtain chocolate. The research of bats, specifically the research of their physiological and molecular mechanisms may have direct applications in human medicine. There were studies done on the saliva of vampire bats, trying to replicate its effect (it prevents blood clotting) in case of patients with stroke, but results were not significant. More recent and more promising is the study of the mechanisms involved in bat hibernation, as well as its application in the treatment of Alzheimer’s patients.

About Alzheimer’s and chocolate we will talk further below, but let’s start with what’s closest to us, in the case of European and Romanian bats. The favourite food of bats on this continent, and thus also bats from Romania, are insects. A single bat can consume, each night, a quantity of insects that equals or exceeds one third, even a half of their own bodyweight. During the maternity period, female bats can consume a quantity of insects that is equal to their own weight. Imagine how it would be if you were required to eat for every dinner about 15-20 kilograms of food! Even if your favorite restaurant invited you to eat for free every night, you would have problems. All of us would.

Even so, bats pass the test with “flying” colors, each bat easily eating 2,000 insects in one night. This means, in the case of a colony of medium size (let’s say 200 bats) into 80,000,000 insects annually. There are documented cases where a single bat consumes 1,000 mosquitoes in an hour, or more than 5,000 mosquitoes during the night. This way, the unlimited appetite of bats has positive effect in areas such as the corn or the wine industry. It is estimated that the largest colony in the world, from the state of Texas, consumes 150 tons of insects each night. This way they bring in massive financial benefits. By hunting and eating insects, bats reduce by over 1 billion $ the annual costs associated with fighting the pests of maize worldwide. The fact that Romania has reached a domestic production of 11 million tons of corn in 2014 is likely due also to the presence of bats.

Stânga: Exemplare ale Tadarida brasiliensis luându-și zborul din Peștera Bracken - A Tadarida brasiliensis kolónia egyedeinek kirepülése a Bracken barlangból. - Brazilian free-tailed bats (Tadarida brasiliensis) emerging from Bracken Cave in Texas. Photo: MerlinTuttle.org Dreapta: Liliac capturând un centiped otrăvitor, el însuși fiind imun la otrava insectei - Mérgező százlábút zsákmányoló denevér, mely immunis az ízeltlábú mérgére - Pallid bat capturing a poisonous centipede, but being immune to its poison. Photo: MerlinTuttle.org

The benefits of the presence of bats are so obvious, that wine producers in Western Europe are trying to attract as many bats as possible to their vineyards. Even the most unpleasant results of the presence of bats, guano (accumulated in the attics of buildings) can be used as natural fertilizer for plants in the garden (although it must be diluted pretty well). Guano contains essential nutrients with nitrogen, potassium and phosphorus.

Leaving aside the fact that the Mayans believed in a bat god called Camazotz, who could cure any disease, bats around us could help in curing some serious diseases and conditions. During their evolution, bats have developed the ability to survive longer time periods without food. Hibernation (which is actually a deep sleep) slows down all bodily functions, and allows bats to endure the winter. The interesting thing from our point of view and from that of human medicine, however, is the awakening from this sleep. In the cells of animals in hibernation there is a protein (called RBM3), which is activated near the awakening phase, to help the brain recover after a latent, inactive period. Scientists currently study the possibility of using this protein RBM3 in patients with Alzheimer’s disease, hoping that understanding and adapting mechanisms observed in hibernating animals will help restore brain activity in Alzheimer patients.

A group of bats is particularly interesting for the fans of modern technology. Horseshoe bats possess one of the most sophisticated guiding mechanisms among animals: a highly sensitive biological radar that uses ultrasounds. Among bat species, horseshoe bats emit ultrasounds with the highest frequency, usually around or slightly above 100 kHz. These sounds, emitted at high frequencies using their biological radar, allow horseshoe bats to obtain such details, as to clearly distinguish between a leaf and a moth …. which is flying at 15 km/h …in the dark. Horseshoe bats can navigate so well with this radar that in many cases they can avoid even those nets, which were initially placed for their capture, by bat researchers. The study of this sophisticated biological radar will most likely have direct applications in ultrasound diagnostics and in increasing the efficiency of radars used on ships, aircraft carriers or airports.

O treime din cantitatea de hrană consumată de omenire se datorează muncii cărăușilor de polen: albine, lilieci și păsări. - Az emberiség által elfogyasztott élelem egymarada a méhek, denevérek és madarak munkájának köszönhető. - One third of the food consumed by mankind exists because of the work or bees, bats and birds. (Bee photo: Todd Huffmann / Wiki, Leptonycteris yerbabuenae bat photo: MerlinTuttle.org. Purple-throated Carib hummingbird photo: Charlesjsharp / Wiki).

For their part, bats from the tropics are key elements in local ecosystems. In these ecosystems with huge diversity there are 200-300 bat species that coexist, and many of them are actually vegetarian: they consume nectar, pollen, fruit and seeds. Nectarivore bats consume the nectar from flowers that are open only at night. In parallel, due to the fact that bats visit dozens, even hundreds of plants every night, this activity has also the effect that the pollen stuck to their face and head (which looks quite cute) is transported to the flowers of other plants, contributing to the reproduction of these plants. For example, the greater long-nosed bat is the only bat species that pollinates the flowers of the agave plant, of Agave tequilana. Yes, tequilana, the plant from which tequila is made. Next time, if you are enjoying a shot of tequila or margarita in your adult life, don’t forget to thank bats.

Other bat from the tropics eat entire fruits and also swallow their seeds. These seeds are carried by bats over long distances and are released, through guano. The microenvironment of guano is already filled with nutrients and this way the seeds prosper quickly in new locations. Thus, among other things, bats are great help in the process of repopulating deforested areas. For free. A single frugivorous bat from the tropics can “carry” up to 60,000 seeds to new locations each night. Among the plants which benefits from this seed spreading activity of bats we can mention a nice example: the cocoa tree. If you love chocolate (don’t deny it, you do), then you should know that bats are responsible for spreading the seeds of the cocoa tree and help us, for free, to produce chocolate.

In essence, vegetarian bats of the tropics do the same work that bees are doing in temperate areas. The importance of bees does not require explanation. It is estimated that one third of the food consumed by humans is obtained with the help of pollen carriers: bats, bees and birds. Overall, more than 450 species of economically important plant species, such as bananas, avocado and mango rely on vegetarian bats to spread their seed or pollen.

Defrișările, folosirea intensivă de pesticide și poluarea luminoasă sunt doar câteva dintre factorii de amenințare pentru lilieci. - A tarvágások, a rovarirtószerek használata és a fényszennyezés csak néhány a denevéreket veszélyeztető tényezők közül. - Clearcuttings, intensive use of pesticides and light pollution are just a few of the threats faced by bats. (Photos: Szilárd Bücs, Flickr & Fernando Tomás).

We can encounter bats basically everywhere. But there is also the chance of their disappearance from around us. And we will definitely note that moment. We will not be able to relax because of a mosquito invasion, nor will we retreat to a room to enjoy a good piece of chocolate. Even those who have the right to consume alcohol will not be able to make a good margarita cocktail.

Despite the fact that bats are protected by a series of laws, their existence is continuing to be threatened by deforestation, damming of rivers, the sometimes irresponsible and disinterested tourism, intensive use of insecticides, or spontaneous renovation of buildings. Sometimes we are misinformed or uninformed about bats and we rather believe legends about hair and blood, and not reality.

It is very important to put aside superstitions and really start to appreciate bats, both for their uniqueness, and for the services they provide us for free.

The original article was published in a shorter form by the same authors (Szilárd Bücs, Olimpia Stan) on Think Outside the Box in 2015.