Birds that roost in communities keep warmer and save more energy than those who roost separately. Another advantage to staying in flocks is that many birds are more likely to find food and detect danger than a solitary bird-several pairs of eyes are better than one. In addition, birds that eat on the ground with their lock can more easily escape attack because at least one member of the lock will alert the others. Then, when all the bird fly upward to escape together, they cause confusion, turning a predator's interest away from any one individual Several small birds may even act together to"mob" a larger intruder and drive it away.