Ants have something similar to blood, but it’s called haemolymph. Some insects use it in unusual ways. When threatened by a predator, blister beetles can squirt haemolymph from their knees.
Travel can come with danger, so dogs have mostly evolved to avoid being over-adventurous. That said, dogs may see some kinds of travel as a chance to find things they want – like food or a mate.
From about age seven, Spartan children learned to fight and practise obeying orders. They also staged pretend battles. Boys and girls were trained separately.
When I was little, geologists worked out Earth’s surface was made of pieces, like a giant puzzle. Those pieces, called “tectonic plates”, move and bump into each other and mountains form.
At the end of the day, the problem is that no-one on Earth wants nuclear waste stored near them, and it’s not safe or cost-effective to blast it into space.
Some colour blind people only have two kinds of cone cell in their eye. Others have three kinds, but the cones do not pick up the same light waves as the cone cells in most people’s eyes do.
Twice every day the Bureau of Meteorology sends out the official weather forecasts for towns and cities across Australia. Here’s how we work out what to say in them.
I’ve worked with NASA’s Mars Exploration Rover Project for 16 years. If you got yourself a ticket to Mars, here’s how I’d advise you to prepare. And by the way, any mistake could kill you.