A Single Teaspoon of Soil Contains More Organisms Than There Are People on Earth

One teaspoon of healthy soil contains around 1 billion bacteria, several metres of fungal threads, and thousands of protozoa, nematodes, and microarthropods. This underground ecosystem drives nutrient cycling, carbon storage, and plant health. Most of these organisms are entirely unknown to science — we've catalogued fewer than 1% of soil microbial species.

Source: Soil Ecology and Ecosystem Services — Diana Wall et al.