I wonder about odd things sometimes.
Such as pigeons. and pigeon babies (squabs).
First, these things are everywhere so they must breed. But why don't we ever see baby or even juvenile pigeons?
Second, do they have nests? I always just see them hanging out on the roof or ground, but I've noticed one or two who nest in the vines at Sendlinger Tor. It seemed like unusual pigeon behavior, though it's perfectly normal for almost all other birds.
Thanks to the Discovery Channel, I've now learned that pigeons do nest, but usually they're hidden completely out of sight and that the babies don't leave the nest until they're almost grown (and are not noticeably different than adult pigeons).
Incidentally, pigeon was one of the first words I learned in German. Working in real estate, I quickly learned some of the common words used in construction and repairs. Taubenabwehr or Taubenabwehrsystem are ones that pops up quite often in the urban buildings. Literally translated as pigeon defense (system), this is the description for the nets and spikes you'll see on buildings with ledges and other attractive perches. What's interesting is that they chose a word for defense that implies an all out battle. Abwehr is a military type defense. Though I think most who have fought battles wtih pigeons would agree on the linguistic choice.