You could talk about how plants supply food for animals.
E.g cacti provide food and water for desert animals and rodents.
small rodents provide food for larger animals and snakes.
some animals will clean larger animals in a mutualistic relationship.
Shore Crabs survive wave action by their shells and their strong claws. When a wave is coming they use their claws to the sand to get grip so the wave won't pull them away, they use their shells in case a rock or something hard in the waves come their way
The answer is glucose.
Hope this helps.
