Watching fireflies glow on a summer night can be heartwarming. Now research shows that same glow may keep your heart beating.

In a recent study researchers slightly altered the chemical that makes fireflies glow and injected it into adult rat heart cells.

They found the chemical bound with cells that produce energy.

So when energy was being produced the cells would light up.

Researchers say knowing how much energy the heart can produce is helpful information for patients who had a heart attack or are recovering from heart surgery.

If the heart doesn't have enough energy it can't perform its pumping function properly.