The three species of mammals that lay eggs are the platypus, 'Echidnas also known as spiny anteaters'.
sit on the eggs
If the eggs don't hatch it mean they were either never fertile to begin with (the goose never mated or the mating never resulted in a pregnancy), or she didn't sit on her eggs constantly and they were exposed to the elements.
that is not true because if you don't sit on your egg it will get cold and the egg has to be warm to keep the baby alive inside the egg
Yes. Kookaburras incubate their eggs by sitting on them. Both the male and female sit on the eggs, sharing their incubation duties.
NO
maybe they sit
maybe they sit
No
The term is Brooding
It's a maternal instinct - in the wild hens / birds sit on their eggs to keep them warm grow into chicks and hatch. Most eggs now are unfertilised but the hen retains the maternal instinct to sit on them anyway.
never