Praying mantises lay egg cases (oothecae) outdoors in late summer or fall.
Christmas trees are grown on outdoor farms, so branches can already have egg cases attached.
The ootheca looks like a small brown, foamy, walnut-shaped lump, which is easy to miss.
When the tree is brought indoors, the warmth can trigger early hatching.
Is it dangerous?
❌ Not dangerous to people or pets
❌ Not harmful to the tree
⚠️ Impractical indoors: the babies will scatter and won’t survive long without food
What to do if you find one
Do not panic
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