Organism that eats other organisms.
This is particularly the consumption of other organisms as energy sources, though for other nutrients as well. That is, whether or not a is a consumer is .
In addition, this especially is other than "consumption" of completely aspects of other organisms. That is, once an organism has been reduced to , water, and carbon dioxide, then the of those substances no longer qualifies as consuming.
See primary consumer, secondary consumer, tertiary consumer, , and secondary productivity (and, to a much more limited extent, simply producer). See also , , decomposer, detrivore, and saprophyte. Furthermore, consider food chains and food webs. Contrast, however, with primary producers.