It's that time of year again: everyone is sticking up decorations, tinsel and - of course - a Christmas tree.
But, what if you knew that you could be inviting a load of weird bugs into your house and providing them with a lovely warm home this winter?
Well, it's not out of the question.
So, when you have a look at your Christmas tree - and you will, now - keep an eye out for brown, hard lumps that look at little bit like pine cones.
They're not pine cones. They could actually be a few hundred praying mantis eggs.
If you've got anyone of these lumps, they'll usually be at the end of the branches, but you'll need to get rid of them quick because if you don't, the warmth of your living room will provide the perfect warm conditions for them to hatch.
This is exactly what happened to Molly Kreuze, from Springfield, Virginia.
She came into her house to discover critters crawling up the walls, across the ceiling, and in the various rooms of her house.
She said: "They're fast. They jump."
Don't worry too much, though. Praying mantises are useful for gardeners as they kill flies and the like. Not so great if they're all over your bedroom, however.
Another concerned person called Daniel recently took to Facebook to warn about the problems that Christmas trees can bring.
It's been shared 180,000 times, so it has touched a nerve.
He said: "If you happen to see a walnut sized/shaped egg mass, on your Christmas tree, don't fret, clip the branch and put it in your garden. These are 100-200 praying mantis eggs!
"We had two egg masses on our tree this year. Don't bring them inside they will hatch and starve!"
One person commented: "Another reason I have a fake tree."
Another said: "If I start seeing things crawling across the floor I will be gone until after Christmas."
Needless to say, this only really applies if you've got a real tree. In the UK, you're unlikely to find a load of bugs in your tree, but if you've bought a Norway Spruce, a Scots Pine or a Fraser Fir, you need to have a look about to check.
It ain't just praying mantises either. Trees can also be a haven for nests of spiders, lice, moths, mites and the like.
So that's something to enjoy this festive season.