Some people have only just found out what the red tree light is for

It's that magical time of the year when Christmas trees are going up and the Christmas lights are being untangled. We all know that putting up your Christmas decorations earlier is proven to make you happier, but what some of us don't know is what on earth the red bulb on our Christmas tree lights if for.

On some older Christmas tree lights you may or may not have noticed what some considered to be a 'spare' tree light thats got a red tip. TikToker @Viznelly was surpsied to learn it's purpose and created a video demonstrating just what it's for.

Watch the video:

@viznelly **I** didn’t know. ??☃️ #christmas #diy #home #homedecor #christmastiktok #christmasdecor #houseoftiktok #cleantok #housework #hometiktok #holiday #tips #hacks #hacksandtips #christmastree #navidad #feliznavidad ♬ It's Beginning To Look A Lot Like Christmas - Bing Crosby

If you're unable to watch the video above, the TikToker removes one of the working light bulbs and replaces it with the red one. After a few moments the lights begin to blink, as if by magic.

It's caused quite a stir and even 'blown some peoples minds' with comments such as:

"I swear to god this app has taught me more in the last year than I have been alive"

"1000% thought they were spares. I have been robbed."

Others were upset that there was no helpful instructions on the box:

"Dude all they had to do was write that somewhere on the box. I wasted so many years not knowing about this"