One day, I noticed that my milk spoiled a lot quicker than normal. Then I remembered that I had drunk straight from the milk carton earlier that week (something that I normally didn't do). I wondered, could my milk have spoiled faster because I drank from the carton?

This led me on an investigation where I uncovered some more dirty truths. These habits seem harmless, but are actually pretty gross. A study at Clemson University put three food myths to the test and the results were shocking. 

1. Drinking from the milk carton

Katherine Baker

Are you ever too lazy to get a cup out to pour yourself a glass of milk, so you just take a swig out of the carton? I'm pretty sure we've all done it when nobody was looking.

While it may be convenient at the time, it is actually gross how many germs it spreads—and it can actually make your milk spoil faster. 

In the study, there were eight times the number of bacteria in the carton of milk that had been drank from directly, compared to the carton that had been poured into cups. This was only ten days after first drinking from the carton.

You won't make yourself sick by drinking from the carton, but your milk definitely won't last as long.

If you're someone who doesn't go through a carton that quickly, then you should stop drinking from it to save your milk from spoiling faster. This will also save you money so you don't have to buy milk as often.

Keeping your milk stored in a cold fridge will help slow the rate of bacteria growth, but it won't stop it. So, if you're sharing a carton with roommates, you should tell them to stop drinking from the carton too. Think about flu season... yuck. Just grab a cup.

2. The five-second rule

Emily Waples

The quicker you pick up the food you dropped, the fewer germs it has on it, right? Wrong.

According to the study, as soon as the food hit the floor, bacteria was spread immediately. They tested how much was transferred by dropping bologna onto tile, wood and carpeted floors. The tile floor transferred the most bacteria (70% of the germs from the floor got onto the bologna). 

Even grosser: bacteria like Salmonella can survive for four weeks on the floor and still transfer bacteria. It might be time to disinfect your counter tops and Swiffer your floors.

Next time you drop your food on to the ground, you should probably just toss it.

3. Double-dipping

Eva Reynolds

We've all been at potlucks and parties where everyone is sharing that delicious Buffalo chicken dip, but we are sharing a little more than just the food.

Dip once, and there aren't that many germs being transferred, but once double-dipping happens, that bacteria count goes way up. 

When a dip has been touched once, 10 CFL/ml of bacteria was found. Dip twice, and that number can go all the way up to 1000 CFL/ml—100 times more than the single dip!

The bacteria from double-dipping spreads the worst for thinner sauces, like this salsa, but there is still bacteria transferred for thicker dips too. 

Double-dipping may be hard to avoid, but you can always transfer the dip onto plates, that way you don't have everyone's hands and dipping vessels contaminating the precious dips.

Thanks to Clemson University, we know the dirty truth of these habits. So, quit drinking from the milk carton, using the five-second rule and double-dipping to stay germ free this year.