Is there something special with grape or will raspberry or strawberry work fine? Assuming it's just the sugar?
This may be propaganda from one ant bait manufacturer, but the claim I heard some years ago is that most people are disappointed when they buy commercial ant bait. Most stores sell one or two types, and many times your problem ants will ignore it. The claim is that ants are really pretty specialized, and you need a local professional who knows the species of local ants and what they'll go for. Some like jelly, or anything sweet.
I guess some like meat, not jelly.
I'd suggest looking around and find out what your ants are after, and see if you can make a good guess about what they'll go for. Pet food maybe? Once you find something, boric acid is relatively safe for humans and pets in modest doses, but deadly to ants and roaches and some other insects. I have not tried borax, but it may work the same.
I suspect our big black ants would go for jelly (they love raiding our kitchen), but I've also watched them carry off bark grubs in a feeding frenzy ... and suspect they'd love brood.