If you are within their vision range, they will approach and "stalk" you until they are at their stalk range. Their light turns out and they stop moving when they're stalking you! However, Goobies are not particularly patient and will lunge if you don't step into their range within a certain amount of time after them stalking you. They each have personalities, so the range of their vision and hearing , how far they like to stalk you, and how often they skip straight to attacking instead of ever stalking depends on the Goobie. Gibby is pretty crotchety, while Gabby is a big fan of staring at you across an open field!