Colinsin29 -
In common (but incorrect) usage, animal often means just mammal -- as in, "is that an animal or a bird?". In the same way, "plant" is often used to mean "not a weed", as in: "shall I pull up this weed, or is it a plant?".
Correctly, of course, as ansteyg says, mammals are just one type of animal, and weeds are plants too.
However, it's not really correct to divide all living things into only plants and animals -- that gives you too many ambiguous ones in the middle.
Most biologists nowadays would divide living things into procaryotes (bacteria etc -- sometimes called Monera) and eucaryotes (everything else).
Then eucaryotes divide (at least) into protista (mostly single-celled stuff), fungi, plants and animals. That gives at least five "kingdoms" altogether.
Have a look at this page:
http://anthro.palomar.edu/animal/table_kingdoms.htm (but don't believe the numbers they give for species of animal...).
You said "amphid". Did you mean aphid, or something else? I've never heard of an amphid.