- 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
