Aphids secrete honeydew. Ants farm aphids for the honeydew. So many of the ants you see on plants are there because of the aphids.

Ants also climb my fig trees and nibble away the ripe figs (which are quite soft). I wouldn't expect them to take a bite of an apple -- unless a bird had already broken the skin so the ants had easy access to the apple flesh.

Afaik, when it comes to the vegetable kingdom, ants are only interested in sweet things or plants which have been damaged by other pests.

Ants will also go after the nectar in hummingbird feeders.

Ants can be pollinators for some plants & they will go after nectar just like bees, butterflies & even some flies.

Some plants secrete nectar from other parts than just flowers - like pores on the undersides of leaves, for instance.

Here is a link that might be useful: USDA - ants

I have seen them on my Golden Trumpet tree and on the false bird of paradise, I have not noticed any damage,and I figured if I had not seen damage yet all should be good, but then again I just noticed them.

I'm not a great fan of ants. I'm a butterfly gardener and they climb the plants and eat the eggs and small caterpillars. There are many types of ants, of course. I'm sure many are beneficial. The fire ants are the worst, in my opinion, but the carpenter ants will also eat the wooden parts of houses.

That makes sense, so maybe it is not just the rains driving them up the plants, it is tasty eggs.

last year I threw a bunch of ant killer all around, I did it just before the 1st frost of the year, I could not tell if it was the quick dip in temps or the the ant poison that suddenly turned so many of my plants brown. So now I am kinda of scared to try and figure out how to control the ants. I have pest control, but they only do the house. I might have to look into other companies.