This is not a likely occurrence. However, sewer rats do travel through pipes and can indeed pass the U-bend and enter the toilet bowl. This can happen when you are going to the bathroom and if the rat is aggressive it may try to bite you. This is of course the stuff of nightmares. Truly the most horrifying thing most people can imagine. Any animal coming through your plumbing and into your toilet would be horrific. There must be a way to prevent this from happening.
But how? Arent the pipes of your toilet narrow? Isn’t the U-bend impossible to pass by design? In truth, there is no barrier or structure in a toilet to stop animals and reptiles from traveling through it. Rats are extremely talented swimmers and they can hold their breath for up to 3 minutes and tread water for three days! For three days they can tread water without drowning. Human children are taught to tread water for twenty minutes or more and it has to be taught. Rats are born with this ability.
If you see a rat in your toilet you should act quickly. Try not to be horrified, lower the toilet seat and lid and put something heavy like a phone book on the lid. Make sure the rat cannot get out of the toilet. You can then call a professional to catch the rat in the toilet and then inspect your home for entrances the rat could have used to get into the toilet.
Large cities are always the epicentre for rat activity, while you will rarely see a rat in your toilet or sewer system in a small rural town in the city it’s a common sight. In fact, there used to be city-hired rodent technicians that would bait the sewer but since the financial crash of 2008 that has stopped. The rats now had nothing to kill them, no predators, and no poison so the population exploded. The rats are now infesting the cities of the world so completely that humans are losing the battle.
That being said, if you have rats on your property or in your home then you will have to hire and pay for a trained and experienced rodent technician to exterminate them because the city no longer deals with the population issue. Maybe someday the economy will grow and heal and the city government will return to dealing with the sewer rat population. Until then we have skilled technicians with commercial-grade rodenticide to fend off the tide of rats infesting our homes and business.