an imaginary line along the middle of the Earth, going from side to side.
There tend to be more bugs in areas with warmer, tropical climates. The people in these areas also tend to be sick more often, and even have lower incomes. Scientists wanted to see if there was a relationship between the bugs in these tropical climates and people.
This set of bits will teach you about one set of categories we use to describe the world around us: biomes.
