Question

Animals and birds fluff up their fur and feathers in winter why?

Answer 1

when they fluff their feathers, there are many air spaces formed which act as insulators and do not let the heat of the body go out, or the outside cold penetrate the body. this keeps the animals and birds warm

Answer 2

By fluffing its feathers, a bird traps many tiny pockets of air to hold in body heat and keep out the cold....When the weather is hot, the bird presses its feathersclose to its body to eliminate the insulating air pockets so that body heat is allowed to escape..