Where are all the Polish children?

I saw very few children in the whole of Krakow when I was there a few weeks ago. I was not just in the city center; I was in Lusina, Kliny, Mogilany, Skawina, Balice, etc.

I was a bit stunned because, after all, it is a Catholic country; I had thought I would see many, many children and large families everywhere.

I saw tourist families in the hotel we stayed in, from the US, UK, Germany and elsewhere with kids and I saw US kids with Polish parents ---but living in the US-- going to Poland on the airplane and on the plane from Krakow back to the US, too---but it was a bit odd to me that I saw very few Polish children while there.

Especially considering it was summer, nice weather, big city, we were at ice cream shops, toy stores, candy stores, touristy places, etc.

My husband said maybe it's because so many young Poles go to the UK to work and have their children there? Or they wait until later to have them until they are more established/can afford it?

Or maybe they don't take them when they go out to the square/to the city/to tourist destinations?

Were many Poles out of the area for vacations in July?

Can someone enlighten me?

I have a 4 year old and I want him to have as many playmates there as he does here. We're moving to Krakow in September).

Most families consist of two children or less.
Some would be at summer camp.
Kids come later in life these days.

well, I don't know about all the children here, but I can tell you how my nephews from Warsaw are spending their holidays:
6yrs old - two weeks with his grandparents in a small town, one week with his parents at Baltic Sea (not Gdańsk though, nor any big cities, they're in Jurata or Władysławowo, a popular vacation place on Hel peninsula), one week with his parents on some small Swedish island on the Baltic Sea, one week with his parents (and other friends/family members) in Italy, a few days with the parents in Wrocław.
17yrs old - as above for Wrocław and Italy and Bornholm + almost one month (but not in a row) with the grandparents, because he can play computer games there (and his parents refuse to buy him a computer, he can only use his father's laptop for schoolwork and occasionally for leisure), 2 weeks at a youth camp somewhere in one of those wild nature places (lakes, forests)