If the problem is at the beginning, in a few days you’ll be done with it.
If there is a big problem, it doesn’t help; you will probably never see results.
Ants were found coming out of the kitchen walls, we sealed the spots with silicone, they came out somewhere else, I fed them all the bait over a period of 3 weeks with a lot of patience and saw no progress at all. They ate it and kept wandering around. The species I had was Pharaoh ants, which are covered by this bait.
There were probably many colonies and it was a harder case..
After a lot of research I found Advion Ant Gel Bait 30g, also a bait but for professional exterminators, which is why it comes in a 30g package. I bought it for €23 from an online agricultural supplies store, I put it on a very small piece of ham to make sure it would be eaten and left it in the sink at night when I was sure they would visit. The trick worked. By morning they had eaten the poison in their effort to eat the ham and had also carried the formula back to the colony. After 2 days I saw them decrease noticeably, in 3 days I see 3-4 wandering around like zombies and in 4 days I found only corpses. Since I went through a lot this summer, I’m sharing the information so people can find it ready-made.