Plants and animals have the following distinct properties:
- Plants live from solar energy by photosynthesis, they use solar energy to make sugar and oxygen out of carbon dioxide, which gives them energy. Animals live from the sugar and oxygen plants created and produce carbon dioxide for their energy.
- Animals can move across the planet while plants are tied to the ground.
Clearly, animals have a harder time to survive with no plants within their reach than plants have without animals coming close. This is logical because solar energy is always there while plants are not.
So my question is: Are there animals that can do photosynthesis? It's obvious that an animal with plant-like stateliness would be non-beneficial since it relies on eating other plants for it's energy and there may not always be plants within reach from it's spot.
But animals using the sun and carbon dioxide for energy production does not sound so stupid.
- Night animals could also gather energy in their sleep.
- Much easier than plants, animals could make sure nothing blocks their sunlight.
- Many animals go through periods of hunger because food is scarce, for some of them this period is paired with high sunlight levels. (the dry season f.e.) (EDIT: This is just an idea, of course photosynthesis requires water, which is absent in the dry season. But still, in warm period with enough water, there's sometimes too much animals to feed from the available vegeation.)
Some things I already took into consideration:
- I know that plants, because they are small in mass (compared to the area with which they can collect sunlight) and static, don't need nearly as much energy as animals do. Is this the main reason?
- I know that f.e. reptiles, but in fact all cold-blooded animals, already use the sun's energy. But they only use the heat from the sun to warm their bodies, they don't photosynthesize.