Question

Animals burrow into deep layers of soil in winter because it is:

• A. very cold
• B. rich in gold
• C. warm
• D. safe

Answer 1

The correct option is C warm

• The majority of insects and other invertebrates hibernate during the winter, since they do not produce their own body heat like mammals and birds it is too cold for them to be active.
• However, 10cm under the ground the soil is often a few degrees warmer than the air and many soil animals are still active, including earthworms.
  

So, the correct answer is 'Warm'.