“Will you walk into my parlour?” said the spider to the fly – so starts Mary Howitt’s famous poem ‘The Spider and the Fly’. But what happens when an ant decides to take up the spider’s offer? Spiders can and do prey on ants. If an ant wanders unsuspectingly into a spider web and gets stuck, there is no way for it to escape; it provides the spider with an easy meal.

It is no wonder then that a wary ant wanted to get rid of a spider I sighted one day – I was observing an orb weaver spider constructing its web on the dried branches of a tulsi plant (holy basil – Ocimum tenuiflorum). On multiple instances, I have observed ants aggressively driving out spiders and other potential predators.

 

The orb weaver spider constructing its web on a tulsi plant. These spiders normally construct a fresh web every day.

With the web half constructed, the spider was resting on a branch.

There was an ant nest nearby. An ant, which was patrolling the plant, took offence to the resting spider and started biting the legs of the arachnid.

Unable to tolerate the bites, the spider escaped into its web.

Undeterred, the ant followed right behind. Despite the stickiness of the web, the ant was surprisingly able to move freely on it.

 

According to a recent study, spiders coat their web with a pyrrolidine alkaloid, which acts as an ant repellent. This prevents ants, which would otherwise be able to navigate a web by walking on the non-sticky parts of the web, from invading their webs. But it looks like this spider hadn’t used the repellent yet, because the ant reached the spider within its web and bit it. It succeeded in driving the spider out of its own web.

 

The ant bit the orb weaver spider within its web. The orb weaver spider evacuated its web post haste and went to a different branch.

The orb weaver spider on a different branch.

Another spider feeding on an ant caught in its web. Spiders inject digestive enzymes into their prey. These enzymes break down tissues and liquefy them; the spider then sucks it up.

 

Jumping spiders, which don’t construct webs, stalk and eat ants. Some even disguise themselves as ants to avoid detection.

 

A jumping spider feeding on what appears to be a newly emerged ant queen.

An ant-mimicking spider. These spiders follow weaver ants, whose appearance they are mimicking, and feed on both adults and larvae.

An ant biting a jumping spider.

An ant attempting to evict a praying mantis.

 

Reference:

https://www.nationalgeographic.com/science/article/spiders-coat-their-silk-with-an-ant-repellent