Question

Due to climate and soil factors, in what biome would you expect to find the fewest burrowing animals

Answer 1

Swamps or maybe those in the desert.  In swamps, the soil is too loose for animals to burrow without it caving in.  In deserts, since the climate "rising" its getting to hot and dry for animals to burrow without the sand caving in when an animal walks above it.

Answer 2

An Alaskan tundra. The soil in tundra is permanently frozen (permafrost), meaning that burrowing would be difficult for most animals.