The differences between flies and mammals that account for this difference are not known.

It is much more interesting when the negotiations are conducted between higher mammals.

The message is that H5N1 can go airborne between mammals.

This correlation is thought to explain about 25% of the difference in sleep amount between different mammals.

The discrepancy between mammals and dinosaurs is even more striking.

There is a big difference between placental and marsupial mammals.

Some theories are that competition between dinosaurs and mammals was the cause, or possibly climate changes.

So, this makes me wonder quite a bit about the physiological differences between birds and mammals.

It is quite possible that there will turn out to be some significant differences between mammals and birds.

This suggests that the difference between mammals is in a common control mechanism.