Like a chicken with its head cut off People who live on farms will likely have seen what happens when a chicken's head is cut off. The bird's body continues to run round in a very disorganised way for some time, so the idiom suggests chaos and confusion. Human have been raising chickens for food for a very long time, so there are plenty of idioms about them. The first thing they seem to bring to mind is a lack of bravery. Typically, children dare each other to do things by shouting: 'Chicken!' Teenagers sometimes play a dangerous game called chicken in which they see how long they can drive on a road facing oncoming traffic. Rulers of countries sometimes make terrible threats until one backs down (a game of chicken). When we decide not to do something because of nerves we say: 'I chickened out'. There's also chicken feed. It wouldn't make much of a meal for a human and thus a small amount of money that we regard as hopelessly inadequate is referred to as chicken feed. 'Twelve dollars an hour? That's chicken feed.' You probably know the proverb 'Don't count your chickens before they hatch'. It comes from the fable of the farm girl with some eggs, who dreams of them hatching into chicks and growing into large chickens which she can sell for a lot of money. But at that point she drops them. No eggs, no chickens, dream over. Go step-by-step and don't count your chickens before they hatch. Rule of thumb We have many precise measuring instruments for making things, but it has not always been this way. In early times, people relied on their bodies for measuring things. Ancient measures and lengths come from the size of a hand, foot and forearm. The village carpenter was unlikely to have more than a piece of string for measuring things and often judged the right distance by using his thumb. (The first joint of the thumb to the tip is said to be a good guide for measuring an inch.) Tailors would have also been likely to judge things by eye and thumb, so to do something by the rule of thumb is to do it by experience rather than strict rule. Good cooks do not usually measure every ingredient: they cook by rule of thumb. If you have been in a business a long time, you will be able to judge by rule of thumb how many items fit into a box. Your experience allows you to make good estimates, so you can use a rough measuring system like a carpenter who uses his thumb. Fairly general principles can also be spoken of in terms of rule of thumb. Although there are many ways to organise material and no rule on the number of pictures used, a teacher who has been supervising projects for years can tell you by rule of thumb how many pages you should be producing for a report.