The phrase "puts a bug in ear" is commonly used to refer to someone convincing or persuading another person to pursue a particular idea or course of action. However, there are a myriad of other synonyms that can be substituted in its place, such as "plants a seed," "plants the idea," "instills the notion," "plants a thought," or "plants a concept." Each of these phrases offers a slightly different nuance, but they all convey the basic idea of subtly influencing someone's thinking and behavior. By using different synonyms, one can add variety and freshness to their language while still conveying the same core meaning.