UCSB Science Line
Sponge Spicules Nerve Cells Galaxy Abalone Shell Nickel Succinate X-ray Lens Lupine
UCSB Science Line
How it Works
Ask a Question
Search Topics
Our Scientists
Science Links
Contact Information
Do animals need sun or not?
Question Date: 2018-02-14
Answer 1:

Animals are heterotrophs, which means that they eat other things, so it's possible for animals to live without sunlight (for a while at least). They rely on the sun indirectly, however, because the stuff that animals eat depend on sunlight. Cows, for example, eat grass, which requires sunlight to grow (plants are autotrophs --they create their own food through photosynthesis, which requires sunlight). Foxes eat mice and birds. Like foxes, mice and birds don't need light to live, but the seeds and other things that mice and birds eat do night light. Food is a source of energy for animals. The ultimate source of energy is sunlight, so in that respect, animals DO need sun.

Best regards,

Answer 2:

This question sounds like it arises essentially from confusion over where animals get their energy. Unfortunately, the answer is not a simple yes or no. It is true that most (in fact, nearly all) animals do not need the sun directly, because they get their energy from food they eat. However, the base of the food chain is made up almost entirely of plants which produce their food using energy they get from the sun. For the most part, this includes caves and the depths of the ocean, because the decaying matter and waste consumed by the resident animals initially came from some location which did have sunlight.

However, some locations in the ocean have features called deep-sea hydrothermal vents which are home to ecosystems that apparently do not require any energy from the sun.

Certain specialized bacteria and microorganisms are able to convert minerals expelled by the vents into usable energy and then become food for other animals living in around the vents. There are also some caves which have ecosystems ultimately based on chemical energy sources rather than the sun.

Answer 3:

The question to this answer depends on how we define the word "animal". If we define "animal" as "all the organisms that belong to the Animalia Kingdom according to current biological classification systems", then no - not all animals need the sun. The ones that we normally consider as animals - dogs, cats, birds, spiders - these certain need some sun. However, there are deep-sea creatures that are also in the kingdom of Animalia that do not need the sun at all. Sunlight cannot penetrate so far into the sea, so for these animals to survive, they must develop ways to survive without the sun. The angler fish (scary looking creature with lots of sharp teeth) is such an example.

Thank you!

Answer 4:

That's an interesting question. Plants need sunlight to do photosynthesis to make food for animals to eat, but animals don't do photosynthesis.

Some animals get no sunlight. Fish in the deep ocean, for example. People sometimes get sad, in dark winters, and light from bright lights makes them happier.

Answer 5:

This question does not have a "yes" or "no" answer.

Animals need warmth, and animals need food. The sun provides warmth, but isn't the only way to be warm. The sun provides light that plants or algae need to grow, and almost all animals eat either plants or algae. This means that, without sun, most animals would die because the plants would die. There are a few animals that eat bacteria that eat chemicals from the hot inner Earth, and they may not need sun.

Answer 6:

Yes, we animals do need the sun. It keeps us warm. The light from the sun gets trapped inside our atmosphere and gives us heat.

We also need the sun because plants need the sun and we need plants. The sun gives plants the energy they need to grow. Plants can take the carbon dioxide we breathe out and water from the soil, and make sugars, starches, and all sorts of other molecules that we eat. They also produce oxygen, which we need to breathe. Without plants, we would starve and suffocate.

Here’s a fun thought experiment. Think about some form of energy and I’ll bet you can trace it back to the sun. Example: The school bus needs energy. It gets energy from gasoline. Gasoline is the remains of dinosaurs and other animals that lived millions of years ago. The dinosaurs ate other dinosaurs or plants, which got their energy from the sun.

Your turn. Can you think of any types of energy that don’t come from the sun?

Thanks for asking,

Click Here to return to the search form.

University of California, Santa Barbara Materials Research Laboratory National Science Foundation
This program is co-sponsored by the National Science Foundation and UCSB School-University Partnerships
Copyright © 2017 The Regents of the University of California,
All Rights Reserved.
UCSB Terms of Use