Required Practical 10

• What is the purpose of a choice chamber in animal movement studies?

  To investigate the effect of environmental variables
• What are the steps to set up a choice chamber for humidity investigation?

  1. Add a drying agent to one side
  2. Place damp filter paper on the other side
• How can light conditions be manipulated in a choice chamber?

  • Shine a light on one half
  • Cover the other half with black card
• Why is it important to control other environmental conditions in the experiment?

  To ensure accurate results for the variable tested
• How should light intensity be controlled when investigating humidity?

  Use a dim even light above
• For example how many woodlice should be placed in the choice chamber?

  12 woodlice
• What should be done after placing the woodlice in the choice chamber?

  Cover the chamber with a lid
• For example what is the duration for recording the number of animals in each section?

  10 minutes
• What should be done after recording the number of animals?

  Gently move woodlice back to the center
• What is the overall procedure for investigating the effect of an environmental variable on animal movement using a choice chamber?

  1. Set up choice chamber with different conditions
  2. Control other environmental factors
  3. Place a set number of animals in the center
  4. Cover with a lid
  5. Record the number of animals in each section after a set time
  6. Repeat the process
• The woodlice were left for 15 minutes before their movement was recorded when investigating the effect of humidity. Explain why?


  • Time to establish humidity / for substance to absorb water / water from paper to evaporate
  • Woodlice no longer effected by handling
  • So that behaviour is typical of that humidity
• Explain how you should ensure the safe and ethical handling of animals:

  • Safely - cover open wounds / wash hands with soap after - to minimise risk of infection
  • Ethical - handle carefully / return to habitat ASAP
• Explain why a mesh platform is used when investigating the effect of humidity:

  To keep woodlice a safe distance from drying agent
• Describe how the effect of an environmental variable on the movement of an animal can be investigated using a maze:

  1)Change environment at one end of T shape e.g. add food source

  2)Place animal e.g. maggot in stem of T

  3)Record whether animal turns towards or away from food source

  4)Repeat with a large number of maggots

  • Wipe / clean maze between trials

  5)Repeat with food on other side of T
• Explain why the same organism is not used more than once:

  • Reduces stress on maggots
  • Prevents chance of learned behaviours
• Explain why a clean petri dish / maze is used each time:

  • Animals may leave chemicals / scents
  • Which influences behaviour of other animals
• Explain which statistical test should be used to analyse results:

  • Chi-squared
  • As data are categorical and comparing frequencies
  • To see if significant difference between observed and expected frequencies

  -Expected = equal numbers on each side