Rats are a rodent with incisors that continue to grow for their whole lives. For this reason, they must chew on hard materials to wear them down. This is the cause of most of the destruction rats cause, from chewing on foundation concrete to making entry holes and chewing on electric wires which are one of their favourites. This could result in a house fire and the loss of everything you have worked for in your life. So if you think you have rats it’s very important you deal with them right away. The most common rat to be found in Ontario is not native to Canada, it is an alien from Norway, hence the name, Norway Rat. This rat has no real predators, especially in large cities like Toronto and New York. They are essentially free to do whatever they want, and they do. There is a video on The YouTube.com of a rat carrying away an entire large pizza from someone’s front porch. This is how aggressive and comfortable rats have gotten living with humans. They are not afraid of you or your pets and can easily scare off a domestic cat or dog. The best option is setting traps, but if that feels inhumane then there are other methods of extermination and control that can be used.
The most important thing you must do is to take away their access to food. If they are indoors make sure to vacuum frequently and to keep all food on your plate and to do the dishes right away, do not leave them in the sink because it will attract the rats. You must store food in hard plastic or glass, glass is best as a rat cannot chew it. Your garbage is very important and needs to be sealed tightly and stored in the garage, making sure the door meets the ground tightly at all points. You will have to drain or remove any water feature on your property, coy ponds are a favourite meal of raccoons and rats need to drink water essentially constantly. Get rid of bird feeders and don’t feed pets or children or wildlife of any kind outside. If you do this the rats may have no choice but to vacate your property on their own to find a place with food.
One of the common causes of a rat infestation is actually impossible to solve without having to sell your home and move. If you live up against a ravine or park you will suffer rodents and wildlife constantly as they endlessly try to break into your home. This can be resolved with properly installed exclusion. Exclusion is the process of sealing up areas and entryways that animals, rodents and even insects can enter. Sealing vents, trenching decks with steel mesh and sealing off your soffits can prevent all kinds of animal or rodent invasion. If you are willing to go around your home and even on your roof then you can do this work yourself. Seal up anything that even looks like an animal could manipulate it. One of the most common entryways is through points on the roof where soffit meets the roof in a deep, wide corner. For rats, you will want to focus on the ground level. Weep vents, wall vents and foundation opening are the most likely entryways.
As for killing the rat without a trap there is both commercial and domestic grade rodenticide poisons that will do the trick but only use these poisons on exterior infestations because if a rat dies in your walls it will cause massive damage as it rots.