Octopi change colours when they become frightened. Normally they are a brownish colour, but can change to green or blue when fear sets in.

The green ring that is formed around the yolk of eggs that have been cooked too long is formed by the chemical reaction from the iron in the yolk and the sulphur in the white part of the egg.

The height of the Eiffel Tower varies by as much as 6 inches depending on the temperature.

AMAZING FACTS