There are animals in Paris. Mostly rats, actually, which you can sometimes observe scurrying around the metro tracks. And pigeons, the rats of the air. Small critters are fewer in between. I guess because nearly all surfaces here are covered in asphalt.
There are upsides to this if you don’t like spiders, for example. And everybody can agree that a place is better if you take away mosquitoes. But, coming from a small city and having had the luxury of growing up in a house with a big garden I cannot shake the feeling of how far removed life here is from being natural. This is by no means a given for all major cities, by the way. There are foxes in Berlin!
Despite its great density of people, Paris can be a lonely place. I suppose that is one of the reasons why people have pets here. Cats seem to do alright, but dogs … What makes you think that an animal that needs the outdoors more than you do would be OK in a concrete jungle? Seeing a fat dog waddling behind his owner breaks my heart.
Well, there is one fat dog in Montmartre that kinda lives the life of a king. He walks around and gets a treat wherever he goes. He’s the dog version of Gérard Depardieu.
One last thought: I only know of one quartier in Paris where you can find cockroaches. Ironically it’s around the Champs Elysees. Makes me smile that the rich there have to deal with those pests, when around Barbes you don’t.