Poison and traps were in wide use at the time of the photos in question and had been for some time.

The only reason that "ratcatcher" is a job that no longer exists is because it changed names to "exterminator", the same way that "secretary" no longer exists as a job and is now called "administrative assistant". Preferred titles have changed over time, but the basic job of killing rats absolutely still exists.

My mother's a secretary

At least in my neck of the woods, a rat catcher's job is primarily monitoring. The rat catcher will trap and bait, but if fumigation is required, they'll call an exterminator.