Why Should I care about…The Black Garden Ant

By November 16, 2019News

Our native Black Garden Ant (Lasius niger), like most insects. Gets lots of bad press. Portrayed as prolific picnic pilferers, invading baskets and making off with any goodies they can carry.

A google search of “Ants” will lead you to Pesticide products, articles on garden and home infestations and advice on how to most effectively exterminate them.

This blog looks at these little guys through a different lens.

Musclebound Ladies

The Olympic weightlifters of the insect world, a worker Ant (4-6mm long, living 1-2years) can lift 20 times her own bodyweight! But do not fear the Black Garden Ant, she does not carry diseases or bite people. She is far too busy at the day job and community work.

Ants form intensively structured societies and live peacefully in communities of up to 5,000, which in fairness is a lot if they do invade your picnic basket! They live mostly under rocks, in soil, in gardens and long grasses or woodland.

Family Business

Ants in a colony are all female and all sisters! Their mother, the Queen (who is bigger at 15mm long, living up to 15 years) stays underground in the hive laying eggs while all her infertile daughters go about day to day work.

In late summer the Queen lays special eggs that give rise to Male & Female flying Ants that swarm and mate. Shortly after ‘having a good time’ the male’s short life ends. Each winged female will set up a new hive to lay her fertilised eggs. However, most of the flying Ants are eaten by birds, providing much needed nourishment for young nestlings at this important time.

Ant Careers

The career women that make up the worker ants have no wings…but varied full time jobs.

  • Childminders devoted to care for eggs and larvae
  • Construction workers that build and maintain the hive
  • Food Shoppers who go out searching for supplies
  • Farmers who farm food for the community

Is that Arable or Dairy Farming?

Well both actually!

In spite of their reputation as food thieves that have been supremely accomplished in the farming industry for millions of years. An example of Arable is the tropical Leaf Cutter Ant who has been farming fungi in South American rainforests for over 60 million years!

Irish Dairy Farming…Ants

Our Black Garden Ants manage herds of Aphids, in the same way shepherds and farmers mind and rear flocks of sheep or cattle. They offer protection to the Aphids from ladybirds and other predators. Sometimes they will even move them to better pastures, by herding the Aphids to the parts of the plant richer in Sap (Phloem) in order that the Aphids can eat well and thus produce more honeydew. Honeydew as the name suggests is a sweet mucus secretion that Ants cannot resist. Ants sometimes massage the Aphids to help them secrete more honeydew.

Sustainable Agriculture in Action

Far from factory farming this is a symbiotic relationship, known as mutualism. The Aphids have the best food, free security service and massage therapy, while the Ants are supplied with a regular source of delicious food!

Next time you see the Ants running up and down a plant covered in Aphids, watch closely. You may have thought they were eating the Aphids but they are enabling them as they nibble and suck away at the plant.

No artificial fertilisers, no pesticides, no cruelty, sustainable agriculture that has excelled for millions of years. Maybe humans should take note!

Pests or Pals?

It’s true Ants encourage and preserve Aphids that damage plants. However, they also aerate the soil by tunnelling underground and assist in the decomposition of materials, contributing to soil fertility, added to this they are an important food source for birds.

So, is the Black Garden Ant a pest or a pal? Like the rest of us, they are mostly good, but not perfect!



Photo Credit – Laura Byrne [2018]





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