I've been using the raid baits but apparently they have done nothing. Will try the terro ones next...

Hmm, I can't say what I used (or I would have)...but it seemed effective to me. That may imply that your species of ants is not attracted to that bait.

If they don't go for Raid is it possible they're not ants? Do you have a picture?

Question: How did they get in? Were your plants outside and got carried in?

Unless you have ants in your house, most ants come in when you bring plants back inside after spending the summer outdoors.

Could you please explain how they got in in the first place?

Thanks,

Jane

The house has ants. We've had them in various rooms over the years. Seems we get rid of them in one room and they return in a different room. I followed the trail from the infested pot to the glass deck door where my setup is. Some of the plants were outside but have been inside since October and that particular phal has never been outside. In this case I believe my house gave my plant ants! I've had bait out for a month but I think I have to change brands. I was about to use orthene but the smell was too noxious for me so I sprayed with orange guard. The ants moved to a different pot! Grrr

Sounds like you need to call in a pest control person. No sense treating the plants if the ants keep coming in. When the weather warms up, stick the plants in a bucket of water. The ants will float out. Leave the plants in the bucket for a few hours.

I do that before I bring my plants in for the winter. It has always worked.

But, it sounds like the ants are coming from your house so there is no point treating the plants. You need to get a guy in to treat the house.

Jane

It probably goes beyond the house. You do need pest control. Ask them to examine your yard as well. if you have had them for a while, it will take a while to get rid of them.

I have the same issue with ghost ants. Ghost ants like to follow each other in a trail and gather in groups. My pest guy uses MaxForce and it works well. He puts the gel in the small plastic container/trap and the ants love it. The ants are attracted to and either die or take it back to the queen. I bought Terro brand because Lowe’s didn’t have MaxForce. I keep the gel on hand for the times I can’t wait for the service call.

Not sure about with an orchid but I used with my plumeria when I had an issue with ants.... I used diatomaceous earth Food grade. Available at tractor supply. Look up the uses on line .... This stuff is great. Once wet it's no longer effective but it will do something overnight. Read up on it. natural and safe.