Evildoers beware — a new soldier’s been drafted into the war on terror. If our color-coded charts and duct tape sent chills up your spine, wait until you get a load of our bluegills.

San Francisco, New York, Washington and other big cities are using bluegills — aka sunfish or bream — to safeguard their drinking water. These fish are highly attuned to chemical disturbances in their environment, and could be able to detect chemical warfare before traditional detection means. When the fish are exposed to toxins, they flex their gills in the same way a human would cough.

Reader support helps sustain our work. Donate today to keep our climate news free. All donations DOUBLED!

Sadly, there are plenty of toxins that could make these freshwater fish “flex their gills,” and Osama didn’t put them there.

Grist thanks its sponsors. Become one.