uf0d8 In aves, body is covered with feathers; while in mammals, body is covered with hairs.
uf0d8 Mammary glands are absent in aves while present in mammals.
uf0d8 Forelimbs of aves are modified into wings which is not the case in mammals.
uf0d8 Aves are oviparous, while most of the mammals are viviparous.
