Hi Cecil,
I am staying in a HDB Flat at the end of the corridor. My neighbours usually place bamboo
sticks along the corridor (horizontally) pointing towards at my Main Door.
When I open the door, I can see them (about 15m away from my apartment) pointing directly
at our Main Door.
My another neighbour also grows thorn-like plants (cactus) with the thorns pointing directly at our Main Door (about 5m away).
Are all these harmful to us and how can we deflect all these "Poison Arrows" in the best
possible way.
Please advise. Thank you.

Hi,
You can use the triangular effect that Cecil talks about. Place two pots of plants on both sides of your main door.