Giant feat by tiny pests

The six-metre-high termite city towers to the ceiling of the Dälhölzli zoo swissinfo.ch

The Dählhölzli zoo in Switzerland’s capital, Bern, is the only zoo in the world that has a termite city.

Back in the late 1980s a queen, her king and a few dozen workers came to Bern to build up a community. Today, the city has over one million residents.

The termites arrived in 1988 from Kenya in order to create a vivarium – a place where insects and animals are kept under natural conditions.

The Bern vivarium takes the form of a giant tower that soars to six metres in height.

The termites have built an eight kilometre network -some of which extends beyond the tower – that they use to gather food and construction materials.

The city is ruled by a monarchy with a strict division of labour, with workers, soldiers and fungi all playing their part.

50,000 eggs per day

But unlike many monarchies, the most important royal member is the queen. She lays 50,000 thousand eggs a day and when she dies, the entire tribe collapses and dies out.

“She’s something like ten centimetres long – like a large, thick, sausage,” the zoo’s director, Bernd Schildger, told swissinfo.

“If you’ve seen ‘Alien 3’ you certainly noticed the alien mother, who resembles the termite queen.”

The king, for his part, is less stately, coming in at about one centimetre in length and of rather slight build compared to his wife.

Monogamy

But despite their differences, the two agree to a monogamous relationship as soon as they start courting.

The opportunity to mate comes once a year in the beginning of the rainy season when about 100,000 sexually mature termites fly away from the nest.

“The male and female meet each other either mid-flight or on the ground,” Schildger explains. “They come together as a couple, then loose their wings, fall to the ground and immediately start producing eggs.”

The queen has an arsenal of workers at her beck and call, 24 hours a day, seven days a week.

They constantly bring her food and transport eggs out of the chamber. Workers also forage for food, feed the others and maintain the nest.

The workers eat sand and small stones, which they bring back to the castle and vomit up. This provides building material used to construct the nest.

Unwanted guests

Soldiers, for their part, act as bodyguards by protecting the nest from unwanted guests such as ants.

When a worker sees an ant, it runs to find a soldier, leaving behind a trail of chemical markers to enable the soldier to find his way to the intruder.

“A soldier communicates by swinging its head from left to right, which acts as an alarm signal to the troops to get moving and attack the intruder,” Schildger says.

They use their mandibles – which are strong enough to cut through human skin – to attack their enemies.

Healing jaws

Termites have long been used in Africa to sew up wounds. They are placed on the wound where they bite the two sides together.

While the termites’ mandibles are locked in this position, their bodies are pulled away leaving an effective suture behind.

But for people living in Bern, the termites do not pose a threat.

Unlike many of their species, they don’t have a thing for wood at all. Their palettes prefer greens such as grass and leaves.

swissinfo, Karin Kamp

Key facts

A queen termite lays 50,000 eggs per day.
The nest in Bern has built an eight kilometres road network.
Their home is a six-metre-high tower housing over one million termites.
Workers live for 80 days while the queen lives for 20 years.
When the queen dies, the tribe collapses and perishes.