Maddy investigates burping cows
We're always being told humans are damaging the planet, but did you know cows are causing problems too?
Cows spend a lot of their day eating grass and scientists say all that munching makes them burp loads of gas.
Unlike human burps, you can't hear them and they just smell of grass, but experts say they still cause damage to the environment.
So scientists are using a special bit of headgear designed to catch the gas to find out how much the cows produce.
The gas is called methane and it's produced when grass is broken down inside their main stomach (they have four in total).
They can't store or use the gas so they get rid of it through burping and it's released into the atmosphere.
Methane is one of the gases responsible for global warming, so scientists are trying to work out if different food would stop cows producing so much gas.
Scientists say although the collars look a bit weird they don't bother the cows and they definitely don't stop them doing what they do best - guzzling grass!