My lo doesn't usually tell me when she's hungry either! When she's fussy and it's been about *that* long (however long that is! Usually 3 or 4 hrs), then I offer and see if she takes it. At 3.5 months, if you aim for after naps, sometimes it's easier to judge. I also know when I hold her head next to my breast, if she turns towards me and opens her mouth, then she's probably hungry! :wink: