RPQ 10 - Investigating simple animal responses

• a choice chamber is a container with different compartments, in which you can create different environmental conditions.

  it can be used to investigate how animals, such as woodlice or maggots respond to conditions like light intensity or humidity in the lab
• • construct a choice chamber using the equipment:
  • petri dish base - subdivided into 2 compartments
  • fine mesh
• 1. to investigate the effect of light intensity on woodlouse movement, cover one half of the lid (including the sides) with black paper. this will make one side of the chamber dark. put damp filter paper in both sides of the base to make the humidity constant throughout
• 2. place 10 woodlice on the mesh in the centre of the choice chamber and position the lid on the mesh so it is lined up with the base below
• 3. after 10 mins, take off the lid and record the number of woodlice on each side of the chamber. try to minimise the amount of time the lid is off, so that the environmental conditions created aren't disturbed
• 5. repeat the experiment after gently moving the woodlice back to the centre. you can use a small, soft paintbrush to help with moving the woodlice if necessary. you should find that most woodlice end up on the dark side of the choice chamber (tactic response to light)
• 6. to investigate humidity, place some damp filter paper in one side of the base and a desiccating (drying) agent (such as anhydrous calcium chloride) in the other side. do not cover the lid with paper. put the lid on and leave the chamber for 10 minutes for the environmental conditions to stabilise before carrying out steps 3-5 above
• you can also investigate simple animals responses using a maze e.g. a paper maze can be used to investigate turning behaviour in woodlice and whether it's affected by light intensity
• for ethical reasons - handle the woodlice carefully and return them to their natural habitat as soon as possible. make sure to wash hands after handling wood lice
• be careful if use anhydrous calcium chloride - an irritant to the eyes and skin and generates heat on contact with water. make sure to wear eye protection
• after being forced to turn in a particular direction, woodlice will often turn in the opposite direction next time they have a free choice. this turn alteration can increase the chances of them finding more favourable conditions bc it means they move into different areas