Our bodies react to infection with 'sickness behavior.' When we're ill we become grumpy and antisocial. This change in mood and behavior is hard to ignore, so it prods us to slow down and take it easy.

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Our bodies react to infection with 'sickness behavior.' When we're ill we become grumpy and antisocial. This change in mood and behavior is hard to ignore, so it prods us to slow down and take it easy.