We’ve all heard the stories. The roommate found an unidentifiable substance in the back of the fridge. The macaroni and cheese grew into furry green mold before someone discovered it. The onion dip you made a week before developed strange brown lumps.

“One time we found this brick of cheese behind the milk in the back of our fridge that was moldy and mushy,” said Alysha Mortensen, a freshman from Afton, Wyo. “It was disgusting.”

Cheese isn’t the only thing that can be found lurking in the corners of the refrigerator.

“I saw this thing way back in the fridge and I opened it. It was noodles, but it was so moldy they were like fuzzy spirals,” said Ashlee Rencher, a sophomore from Poulsbo, Wash.

Rotting cheese and prehistoric pasta are proof that knowing when to toss the leftovers could prove to be health-beneficial.

Each year, 76 million Americans fall sick with food-borne illnesses and 5,000 die of them, according to the Center for Disease Control and Prevention.

These illnesses could be prevented with a few easy steps.

First, keeping track of when you purchased and opened the food is very important, according to Prevention.

An easy way to do this is to keep a marker handy and date your food as soon as you get home from the grocery store.

Next, keep your refrigerator below 40 degrees Fahrenheit, because anything warmer can harbor bacteria, according to Prevention.

Keep your freezer at 0 degrees for maximum storage capability.

Refrigerating or freezing leftovers before they’ve been at room temperature for two hours will keep most harmful bacteria from multiplying, according to an article in Environmental Nutrition.

The article also warned against packing the refrigerator too full, because air must be able to circulate to keep food safe.

Kathy Cook, who teaches nutrition classes at BYU-Idaho, warns students to clean the fridge on a regular basis and rotate the food in the refrigerator.

“If in doubt, throw it out!” Cook said.