Differences between mammals and animals are:
• Animals could be either ectothermic or endothermic, but mammals are always endothermic.
• Only mammals have hairs on the skin out of all the animals.
• Only mammals have mammary glands and sweat glands out of all the animals.
• The most sophisticated heart and the circulatory system are present in mammals out of all the animals.
• Mammals have more complex living habits (e.g. human) than other animals.
• Number of mammals is only a fraction compared to the rest of the number of animals.
• Some mammals are capable of singing, but other animals are not.