Unless it's a virus.
See, there's actually a number of characteristics science requires to define life (a lot of which were added to prevent
fire from counting as a living thing). Per Study.com:
- Reproduction - For something to be considered alive, it must be able to reproduce and create offspring.
- Heredity - Heredity is the ability to pass on genetic material (DNA) from parent to offspring. This can be in the form of phenotypic traits (the way a living thing looks on the outside) and genotypic traits (the actual genetic code that determines how something behaves and looks).
- Cellular Organization - All living things are composed of one or more cells.
- Growth and Development - All organisms develop over time to become more physically and mentally mature.
- Adaptation Through Evolution - Every living thing has evolved at some point in time, and continues to do so in order to adapt to an everchanging environment.
- Response to Stimuli - Living things respond to stimuli in their environment.
- Homeostasis - Homeostasis is a living thing's ability to maintain stable internal factors, such as blood pressure, body temperature (thermoregulation), and water balance within cells.
- Metabolism - An organism must use chemical reactions to process and/or use resources from the environment in order to continue functioning.
So pretty much all undead already hit 3, 6, and 7.
There's really no reason they can't also do 1 and still be comfortable considered Not Alive since fire does 1,4*,6,7, and 8 and viruses do 1,2,3,5,6, and 7
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