Ants’ self-medication, new research


This video says about itself:

Leaf-Cutter Ants Biology 1210 – 2014

2 April 2014

Why do Leaf-Cutter Ants Make Good Farmers?

From daily The Independent in Britain:

Ants are able to ‘self-medicate‘ by changing diet when they are unwell in first for insect-kind

Findings of study raise questions over how ants ‘know’ they are sick

Jessica Staufenberg

Saturday 22 August 2015

It appears that ants, usually seen as the ultimate self-sacrificing workers, are also not bad at saving their own skins.

Scientists have shown that ants with a life-threatening fungus are able to “self-medicate”, eating a normally harmful substance that treats the condition.

This form of “self-medication” in insects has been suspected in research circles but has never been proven until now, raising questions about how the ant “knows” it is sick.

Researchers at the University of Helsinki in Finland showed that ants infected with the fungus Beauveria bassiana would choose to eat small doses of hydrogen peroxide, which had been proven to reduce their deaths by at least 15 per cent.

The fact that most healthy ants gave the poison a wide berth – since it usually caused a 20 per cent mortality rate – appeared to show that sick ants knew the poison would help them recover.

Depending on how strong the toxic solution was, the infected ants would also either choose to eat the poison as often as normal food, or only a quarter of the time, showing they were “careful” about their selecting their doses.

Nick Bos, one of the researchers, said ants close to death in the wild also seem to know because they often leave the nest to die in isolation.

“It is not known yet how ants know they are infected, but it’s very clear that they do somehow change their behaviour once they are,” he told the New Scientist.

Jessica Abbott of Lund University in Sweden, said the study stood up to scientific scrutiny.

“I think this is good evidence of self-medication,” she told the New Scientist. “They showed that the ants deliberately ingest hydrogen peroxide when infected – and that doing so increases the survival of the ant and decreases the fitness of the parasite.”

The chemicals found in hydrogen peroxide are also present in aphids and decaying dead ants, leading the Finnish team to say ants in the wild may eat these to fight off infection.

David Baracchi of Queen University of London said that social insects in large colonies like ants and bees are vulnerable to disease, and a small percentage increase in survival rates against infection could make a huge difference to a colony.

“It is natural that they have evolved amazing mechanisms to counteract microorganisms, and self-medication is one of those,” said Baracchi. He added it may be a widespread ability in the animal kingdom (a similar phenomenon has already been found in sheep).

This new study was published here.

Ants transporting dead beetle, video


This video is about ants transporting a dead beetle on a sidewalk in the Netherlands, while meeting obstacles.

Everdien van der Bijl made this video.

Ants attack dragonfly, video


In this 16 June 2015 video, wood ants attack a four-spotted chaser dragonfly which had just metamorphosed from the larval stage.

Warden Erik Bloeming of the Bargerveen nature reserve in Drenthe province in the Netherlands made this video. See also here.

Dutch ants helped by tunnels


This video is about Formica polyctena and Serviformica cinerea ants.

Translated from the Dutch entomologists of EIS Kenniscentrum Insecten:

Tuesday, June 2nd, 2015

In Venlo, Formica polyctena ants are threatened by the construction of roads and an industrial area and more recently by the construction of the Floriade flower show. On the Floriade site in 2012 there came a unique solution to prevent fragmentation of ant habitats, special ant tunnels were built. Now it is full spring, the ants are busy collecting food and the tunnels are still in use.

Ant tunnel in Venlo

This photo by Arjan van den Bosch shows an ant tunnel in Venlo.

Black woodpeckers catch ants for their chicks


This video is about a black woodpecker couple, breaking an anthill open.

They want to feed the ants to the hungry chicks in their nest.

Hans Wolters in the Netherlands made this video.

Ants have their own Highway Code, new research


This video is about Formica pratensis ants.

From Wildlife Extra:

Researchers find ants have their own Highway Code in high traffic areas

Researchers in Germany have discovered that ants have a sophisticated code of conduct in high traffic areas and their own rules of the road, according to new research published in Springer’s journal The Science of Nature – Naturwissenschaften.

One of the scientists’ observations is that ants speed up in response to a higher density of traffic on their trails, rather than slowing down as might be expected.

Not surprisingly, when the researchers increased the supply of food by leaving it next to the trail, ants accelerated their speed by 50 per cent. What was unexpected was that this was despite more than double the density of traffic.

When food increases in supply, more forager ants are sent out to carry it back to the nest. With this increase in ant density, the number of encounters between outbound and incoming individuals increases.

Researchers at the University of Halle-Wittenberg in Germany suggest that the encounters provide an opportunity for ants to swap information and to change their behaviour according to conditions.

Rules of ant etiquette were also observed. For example, workers returning to the colony more often moved to the left than to the right to avoid colliding with an oncoming ant.

Rather than segregating strictly into lanes like human traffic, the ants used only a degree of segregation, with inbound ants more frequently using the left side of the trail.

The observations were made of the black-meadow ant, Formica pratensis, a species that lives mainly in open grassland and forages on aphid honeydew as its carbohydrate source.

The colonies studied were situated near favoured foraging sites where the ants protect and cultivate aphid populations. Repeated journeys in these colonies are made more efficient by the use of well-worn trails that can persist for over a decade.

A total of 1,865 individual ants were filmed on a 15cm (6in) section of trail. The video was stopped every 50 frames and the number of ants on each lane was counted. At low and medium densities, ants preferred the central lanes.

Of the total number, 496 ants were also studied for their speed. Encounters between ants included touching antennae or exchanging fluids. The number of encounters increased with density but this did not reduce the traffic flow.

“Even under the highest densities we could achieve, we did not observe any traffic jams,” says Christiane Hönicke, co-author of the study. “The ants increased their pace and were driven off the central lanes of the trail, resulting in a self-organised optimisation of the traffic.”

Ant carrying bee, video


In this video, an ant carries a dead, much bigger, Andrena vaga mining bee to its anthill.

Matthijs Herremans in the Netherlands made this video.

Andrena argentata bees on Texel island: here.