Health officials are warning people and pets to avoid bodies of water that look like pea soup.

Rock County Public Health Officer Katrina Harwood says children and pets are most at risk of becoming sick from blue-green algae.

Blooms sometimes look like foam, scum, mats, or paint on the surface of the water.

Blooms are more likely when water is warm, slow-moving, and full of nutrients such as nitrogen or phosphorous.