Do you have any custom houses that you downloaded? I don't know if this kind of hack might accidentally get included, but I have heard of downloaded houses sometimes having extra hacks accidentally included because the person who made it had it.
Only one mother? That is so odd! Lol.
No, I have downloaded no custom houses. I was always afraid of getting hacks I didn't want.
I do have quite a number of hacks loaded via sim-unpack which have those hex-digit names, but I've had those for ages, and they're all (as far as I know) clothing or other items, none of them are behavioral hacks. It's only recently, since I started using a number of other hacks and then upgraded to NL (for a long time I was just running Uni), and then had to look for NL versions of some Uni hacks, that I've seen this behavior. I'm a great fan of Pescado's hacks on MATY, and have adopted a number of those, also, as I said, InTeenimator and (for occasional use) the InSimenator.
Since my original post, I've seen this 'feed baby' come up autonomously on a couple of occasions with other mothers, but it's still, so far, only a selectable menu option on the one mother. It comes up as a sub-action on the 'hold baby' action, not as an action in its own right (like the 'kiss' options on 'cuddle' etc).
Oh, and Squinge, I'm sure there's nothing wrong with your hack, just that I never really felt a need for it ;-)