Potato plant flowering

I came upon the potato flowers early in the morning, lit up by the sun rising. I really don't know what the ant is doing on it but I have ants all over my plot so this is par for the course.

Lately, I plant potatoes in containers. This plant is now flowering, which does not always happen, and I don't know why. In the past, I have used 15 gallon containers for potatoes, and it is quite the mystery to me why I have not had good luck with that size. Since downgrading to a smaller size container, I have found the plants to be much happier. They grow tall and overflow the container.

This flower reminds me of its relation to tomatoes and eggplants as they are all in the same family, Solanaceae.