Q: Can a package be suspicious or does it need a person to be suspicious of it?
A: The adjective “suspicious” can properly be applied to a person who entertains suspicions, or to a person or thing inspiring suspicion in others.
So, a package with a ticking noise inside may indeed be suspicious, though someone or something (a nosey cat, for instance) must suspect that something is up.
The Oxford English Dictionary has these definitions under its entry for “suspicious”:
(1) “Open to, deserving of, or exciting suspicion; that is or should be an object of suspicion; suspected, or to be suspected; of questionable character.”
(2) “Full of, inclined to, or feeling suspicion; disposed to suspect; suspecting; esp. disposed to suspect evil, mistrustful.”
Interestingly, the first definition (the one that would apply to that package of yours) is the oldest, dating back to the early 14th century.
In The Canterbury Tales, for example, written around 1386, Chaucer describes a sergeant’s reputation (diffame in Middle English) as suspicious: “Suspecious was the diffame of this man, / Suspect his face, suspect his word also.”
It wasn’t until around the beginning of the 15th century that people, as well as things, could be suspicious. Now, who would have suspected that?