What is 'reindeer food'?
Well, according to a few craft websites, it's a mixture of oats, glitter and sequins that you sprinkle on your lawn for Santa's reindeer to eat when they visit.
Making it is a great way to keep kids occupied in the run-up to Christmas - but if you put it in your garden this year, you might be harming the local wildlife.
The RSPCA posted a warning on Facebook not to sprinkle 'reindeer food' on the ground, as the sequins and glitter in in the mixture will harm small animals if they eat them.
"Urgent plea to save garden wildlife from harm this Christmas!" read the post.
"If your child has made pretty reindeer food please do not 'sprinkle on the lawn' as the labels suggest as many of our very hungry small garden birds and mammals could ingest the plastic and foil glitter along with the oats potentially causing long term damage to their digestive systems.
"Please instead leave in a small bowl indoors alongside FC's mince pie. Thank you and Merry Christmas!!"
Reindeer food is popular on Pinterest. Many of the 'recipes' for it online suggest using edible cake decorations instead of sequins, but while these might seem safer, they're still not meant for animal consumption.
So, if you've made 'reindeer food' with your kids this Christmas, make sure they know that the reindeers will, of course, be entering the house with Santa, so there's no need to sprinkle it outside.
Did you make reindeer food, or is this the first time you've heard of it? Tell us at Closer's Facebook and Twitter