Fortunately, there's a very simple way to tell a plain mirror from a spy mirror. Just place your finger close to the reflective surface:
- If there is a small gap between your finger and its reflection, the mirror is normal.
- If your finger seems to be stuck directly to its reflection, beware: it may be a two-way mirror.
In this case, don't take any chances: change hotels immediately to protect your privacy.

Neglected toilets: a real breeding ground for bacteria
There's nothing more annoying than a poorly maintained bathroom. But beyond being a mere nuisance, limescale-covered faucets and shower heads can also indicate serious hygiene deficiencies.