Should I be concerned about ants?

Off and on I have noticed from time to time very small black ants climbing over my plants, normally it is only one or two but today I noticed quite a few climbing in and over my plants. None of my plants have any damage /yet/ so I was not concerned. They are the very small ants found in Far North Queensland. Not sure for the proper name but we all call them "sticky ants"

I didnt think they would do anything so have pretty much ignored them.

But now after checking google Im not so sure... should I be proactive instead of waiting for damage and being reactive.

Will they even want to have a chew on my cacti?

If you think I should spray my greenhouses could you please recommend a good product as believe it or not but I have never sprayed them before as "touch wood" have never had any bug issues.

Ants don't usually pose a great problem to the plants by themselves. They're attracted to the nectar glands that some Cactis like Fero's have.

That being said, here's three reasons not to want ants in your greenhouse -

1. It's said that ants can actively spread mealy bug throughout your as they "farm" them and move them from plant to plant

2. They will steal any seed you plants produce. To the point of cutting open the pods and taking it just as it gets ripe!

3. They can nest in your pots and remove the soil from the plants...

I am thinking of putting a layer of grease around the bottom of my next plant house and making sure no shrubs lean on it to keep the ants out. They definitely bring in scale and mealy bug from outside, so if you are being very careful with quarantine then it can be worth doing. If you are bringing in whole potted plants from other growers without unpotting, soaking in insecticide, potting in fresh clean soil and then still keeping them apart from your main collection for a few months then I wouldn't worry about them- most pests are brought in on infected plants.