I fear they have already infiltrated and then they breed - some of them morph into button holers and old zig zag attachments that don't fit anything or junk sewing machines - there may be something that gets into the air then consequently into the blood - then before you know it old sewing machines invade your space until there is none left and the rest of the family thinks INTERVENTION - all they needed to do was find the trojan... its still there somewhere...