If you mean why are they are not skeletons as a life form then the dull answer is that a living mammal needs a bloodstream and muscles, and tissue and so on. Most insects and spiders are basically skeletal.
what is the colour of the blue and orange colouration in methyl orange
A mammal because if you think about it is a deer so a deer a is a mammal so it is a mammal too.
if you mean colouration then no if they don't have a lot of colouration it means there stressed
Everyone can be dull from time to time. Answering questions can come with many surprises from dull to exciting!
A nettle is a plant, so it is not a mammal.
Teachers are not usually dull. What seems to be dull are their teaching techniques or the students' willingness to make learning an enjoyable process.
To use the word "dull" in a sentence, you could say: "The lecture was so dull that I struggled to stay awake."
Do you mean cygnet? If so this is a baby swan. So it is a bird not a mammal.
The lecture was so dull that most of the students fell asleep.
An elephant is a mammal, and has a backbone, so is a vertebrate.
a nonmetal because a metal is shiny and strong so a nonmetal is brittle and dull