Ants build en-suite ‘TOILETS’: Insects use allocated corner of their nest as lavatories – and use the waste as manure
Source: PESTWEB Date: 24 February 2015
Biologists at University of Regensburg studied common black garden ants.
They fed the ants sugary food containing coloured dye to track their faeces
After two months they found distinct piles appeared in corners of the nests
Scientists say the insects may use their waste for building or as fertiliser
| Updated: 13:42 EST, 19 February 2015
In the cramped conditions of an ant nest, living alongside 100,000 of your work colleagues could get a little messy.
Black garden ants, however, appear to have a solution – they build en-suite toilets in the corners of their nests.
Biologists have found that the insects are meticulously sanitary when it comes to where they deposit their faeces – leaving them in just one or two places.
But rather than throwing out the build-up of waste like they do with other rubbish – such as the remains of food and corpses – they leave the toilets in their nests.
It suggests that the ants may use put their faeces to some use – perhaps even using it as a place to ‘grow’ food.
ANTS MAY BE LEFT-HANDED
While humans and even crows have been found to have a favoured side when performing delicate tasks, it also seems ants may do too.
A recent study has found that ants tend to turn left when exploring new surroundings.
The behaviour was recorded when Temnothorax albipennis, or rock ants, were put in mazes.
In the experiment the ants overwhelmingly chose to turn left, as opposed to right, when exploring the new ‘nest’.
Why ants may have this bias for the left remains unknown, according to biologists.
Dr Tomer Czackzkes, a biologist who led the study at the University of Regensburg, in Germany, said: ‘For ants, which like us live in very dense communities, sanitation is a big problem.
‘Ants normally keep a very clean nest, and usually throw out dangerous rubbish, like food remains and corpses.
‘Some insects use faeces for defense, as building materials, as manure for their crops, and as markings.
‘Perhaps these toilets are also gardens for crops, or even stores for valuable nutrients.’
The researchers, whose study is published in the journal Public Library of Science One, observed the behaviour of black garden ants, Lasius niger.
They were kept in nests built from plaster and given sugary food dyed with either red or blue food dye.
The scientists then took pictures of the nests and surrounding foraging box they were placed in over the next two months.
After two months the ants were removed and the scientists found coloured patches had formed in one to four corners of the nests.
The colour was always the same colour as the sugary food the ants had eaten.
The scientists said that no coloured patches were found outside the nest, but distinct piles of dead ants and other debris from the nest were found outside.
They also gave the ants a protein jelly – which worker ants do not eat and can be lethal to them – and this was also found outside the nest.
Other social insects are also known to collect their faeces for use – termites use it as a building material while leaf cutter ants use it as fertiliser for the fungi they use as food.
Honeybees, however, are known to leave their nests to go on ‘defecation flights’.
Dr Czackzkes said the toilets may have an anti-microbial function to help prevent the spread of disease in the nests.
He said that there did not appear to be any fungi growing on the toilet areas, but when ants were removed from the nest some fungi did grow.
He also noticed that the ants did not appear to avoid walking through the toilets and is keen to investigate whether workers carry the brood to these areas of the nest or keep them away.
He said: ‘The growth of micro-organisms on the toilets may be actively inhibited by the ants, perhaps by the application of formic acid or antibiotic secretions.
‘Alternatively, the ants may be using the toilets as a garden, and eating the resulting fruiting bodies, as a way of accessing otherwise inaccessible nutrients from their waste.
‘These hypothesised roles for the toilets are open to future investigation.’