the classification for chickens is poultry.
a herd is just another name for a group of animals, a more scientific name. other types are flocks, crashes, etc.
Yes "arboreal" animals.
A group of crows are called a murder ...
arachnids
There is no collective name for a group of platypuses. Platypuses are solitary animals and do not live or move in groups.
Exoskeletons
blue bird,hawk
biosphere, ecosystem,
They are called ectotherms.
Amphibians
Sterol
Chordates.