TikToker Lena has shared a video explaining hacks every travellers should know when staying in hotel rooms.

The clever video has racked up more than 35 million views online.

She said: "First, by sealing a piece of paper with moisture over the door, you can detect if someone entered your room while you were away. Second, the video reveals how to check if a mirror is real or a two-way mirror."

Someone Could Be Watching You in Your Hotel Room ! This viral video (35M+ views across social media) demonstrates two simple but powerful safety hacks for travelers staying in hotels. First, by sealing a piece of paper with moisture over the door, you can detect if someone entered your room while you were away. Second, the video reveals how to check if a mirror is real or a two-way mirror — using only tape and a marker. Practical, eye-opening, and highly shareable, this content is ideal for travel, lifestyle, and safety-focused brands looking to engage audiences with valuable tips.