In the Third World (as we used to call it before we decided they were developing), the most popular beast of burden is not the horse, the ox, the yak or the llama.
It's the combustion engine - specifically a two-stroke motorbike, often adapted into a three-wheeler tuk-tuk. And by goodness do some people work those little engines hard.
When I was in India earlier this month, I used to play a little mental game to ease my nerves while being propelled through the mass deathwish that is Indian traffic.
Basically, I couldn't shut my eyes to the perpetually imminent risk of horrific accident, so instead I'd try to distract myself by counting the people perched on the back of motorbikes or in the seat of a three-wheel tuk-tuk.
I soon developed a mathematic theorem to describe the maximum number of people per vehicle by reference to the number of wheels. Basically, 2 to the power of the number of wheels is the maximum.
For the innumerate, that means 2 X 2 (4) on a motorbike, 2 X 2 X 2 (8) in a tuk tuk, and 2 X 2 X 2 X 2 (16) in a car.
However, I was soon proved wrong. Within days, in Jaipur, I saw a tuk-tuk (which is built to carry three people, including driver) carrying TEN people in total. And five on a motorbike became a regular sight. And I never saw more than four or five in a car (because cars in India are for the rich and they don't like to be crowded out.)
I was in Cambodia in the past too, and they're also big fans of overcrowding their metallic beasts of burden. But I can honestly say I never saw eight people on the back of a bike before.
But there you go. Four adults and four kids (plus a bag of shopping and large tin of something heavy looking) all on one little motorbike. If you squint you might see some of it between their many legs.
It's a chastening thought for anyone sat alone in their car in Ireland, giving out about the traffic.