Not Like the Rest

Ponder the pest It's not like the rest: Can't stick out its chest Doesn't have a nest Your crops it infests Devours and ingests Acts rather stressed Promotes such unrest... It's not a good guest It flunks every test It's certainly not blessed its presence you detest It exists to molest It's often hard-pressed It's best when obsessed Yet may I suggest Somewhat in jest At its progenitor's behest ~ With your head it has messed.