As the festive season reaches its peak, a hidden hitchhiker in real Christmas trees is prompting urgent warnings for households across the UK. Experts and social media users are alerting families to be vigilant for a specific, unusual feature on their trees that could lead to an unexpected insect infestation indoors.
The Hidden Hazard in Your Festive Fir
The cause for concern is a brown, walnut-sized, solid cluster that bears a close resemblance to a small, compact pine cone. This innocuous-looking object is, in fact, often a cocoon or egg case (ootheca) of the praying mantis. A single one of these cases can harbour between 100 to 200 individual praying mantis eggs.
Natural Christmas trees provide perfect camouflage for these egg sacs, which are typically laid on the tips of branches. The danger arises when a tree carrying these cases is brought into a warm home. The consistent, cosy indoor heating can trick the eggs into believing spring has arrived, triggering them to hatch prematurely.
Social Media Sparks Widespread Alert
The warning has gained significant traction online, particularly through platforms like TikTok. Content creator Lexi Natoli shared a widely-viewed clip advising viewers: "If you see this on your Christmas tree, get rid of it immediately... When you bring the tree inside, the warmth of your house will cause them to hatch and you will have hundreds of preying mantis' running around your house."
The video prompted a flood of reactions from the public, ranging from concern to dark humour:
- One user shared a cautionary tale: "We found this and didn't know what it was... And one day, thousands of babies were all in the car."
- Another commented on the reason for their artificial tree preference: "Stuff like this (and stories from my firefighter grandfather) are the reasons why I will never get a real tree for Christmas."
- Others saw a silver lining, with one person stating, "I'm so excited to raise a colony of praying mantis'."
Practical Advice for UK Households
The key advice for families who have chosen a real tree this year is straightforward: inspect your tree carefully before and after bringing it indoors. Pay close attention to branch tips and junctions. If you discover one of these distinctive brown lumps, the recommended action is to remove the egg sac immediately and dispose of it outside, away from your home.
It is crucial to note that this warning only applies to real, natural Christmas trees. Furthermore, while the online discussion has caused alarm, encountering these egg cases in the UK is considered quite uncommon. However, given the potential for a significant hatchling event, a simple visual check is a small step that can prevent an unsettling festive surprise.
The story was originally reported by Jess Flaherty, Senior News Reporter, and Jane Lavender, Associate Editor, on December 16, 2025, highlighting a seasonal reminder that blends nature with our traditional holiday decor.
