When multiple people independently comment on someone’s demeanor or appearance as being unsettling, sinister, or “weasel-like,” it usually means there’s something instinctively off-putting about them. Humans are pretty good at picking up on subtle cues—body language, facial expressions, energy, or even micro-expressions that indicate deception, malice, or manipulation.

Some people just have an untrustworthy or eerie presence, whether it’s their posture, how they avoid eye contact (or stare too intensely), their smirk, or even the way they move. A person who gives off a “weasel-like” or “sinister” vibe might be someone who exudes sneakiness, shifty behavior, or insincerity. And if a lot of people pick up on it, there’s probably a reason—whether it’s conscious or subconscious.

That said, sometimes looks can be deceiving, but when it’s both appearance and behavior setting off alarms, it’s often a red flag.