Energy in Food Chains and Webs
Look at the information below about the feeding habits of woodland animals. 
•	-Hedgehogs eat slugs and beetles 
•	-Ladybirds eat greenfly
•	-Thrushes eat snails and some types of caterpillar
•	-Some types of beetle take sap from plants, while others eat greenfly and ants
•	-Foxes eat thrushes and slugs
•	-Snails and slugs eat most types of leaf 
•	-Greenfly suck sap from plants
•	-Ants eat any type of plant parts
We know that the plants in the woodland trap sunlight energy to make food in a process called photosynthesis. 

 1. Construct a diagram using the animal pictures, to show where this 
 energy is transferred to as the woodland animals feed. This is an energy 
flow diagram. 
2. Compare your diagram with another group and see how similar or how different it is. Stick your diagram into your exercise book and write down the ways in which your diagram was the same and different to the other group. 
The next set of data shows results of animal counts of the woodland animals 
-Foxes		 2 
-Greenfly 		46 per sq. metre 
-Hedgehogs 		4 
-Ladybirds 		5 per sq. metre 
-Slugs 		11 per sq. metre 
-Snails 		16 per sq. metre 
-Thrushes 		3 

3. In your group look at this information and think about how this data fits in with your energy flow diagram and the feeding habits of the animals. Describe in your books any relationships that you can see. 
4. Some animals’ counts are missing; in your group decide which these 
animals are, write down what you think their count is likely to be and give a reason for your choice. 
 GROUP DISCUSSION. 
A new housing estate was built on the hill above the woodland. After three years, scientists recorded a decrease in the number of some woodland animals and an increase in the number of others 
5. One theory was that a molluscicide (a chemical that kills snails and slugs) had got into the soil water from the gardens on the housing estate and leaked down the hill into the wood. If this was the reason, for the change in numbers of different animal groups, what sort of numbers would you expect and why? Write down all of you reasons. 
6. Another theory was that a new type of beetle had moved into the wood, which fed on greenfly and ants. This beetle also produced a bitter tasting chemical when attacked that stopped hedgehogs eating it. If this was the reason for the change in numbers of different animal groups, what sort of numbers would you expect and why? Write down all of your reasons 
7. What other theories can you think of? How would these affect the animal numbers in the wood? Write down all of your answers.
GROUP DISCUSSION