It's a proverb, which is old but still useful to understand Closed mouth catches no flies This proverb came from the situation that a frog if sitting idle and having a closed mouth, no flies will be caught in the mouth which results in no flies coming in it. But if mouth is open and he rolls the tongue the flies may come and he may eat It's just a natural part of life But in human life we can correlate it with a meaning Always be ready to grab the opportunity Always stay active so that the opportunity can