How to prevent squirrel/raccoon/other animals building nests in the attic ?

Cut down all branches close to the house.
Make sure the soffits are secured (not loose).

These animals can scale walls , climb downspouts , etc. Smaller rodents like mice can even get in through weep holes. Cutting branches makes no difference.

I believe most animals getting into the attic usually squeeze in through damaged or loose soffits, but larger animals like a raccoon could probably pull up shingles and dig through if they really wanted to.

There are companies you can hire to seal off your home but they are very expensive.

Try to block any obvious paths to the roof, but as others have pointed out, many of these animals can climb anything. You can also try to block any obvious entrances, make sure there are no holes, but it's virtually impossible to seal everything, and again these animals can chew and claw their way through most barriers except solid metal.

Raccoons really go to town on cedar shake roofs, where they can easily rip up the shakes and break through the underlay to get into the attic. They don't do that with asphalt shingle roofs because there is normally a deck of solid plywood underneath that's too difficult to get through. Don't ask me how they know that (smell? feel on their little raccoon feet?), but they do.

Most of these animals are nocturnal, so it's best to block entrances at night while they are out. Otherwise for larger animals you can put a one-way trap on the entrance that lets them out but not in, Keep it in place for a few days.

For rats and mice you can put traps with bait in the attic. You should catch any that get in, or you will at least see evidence of their activity pretty quickly and know to hunt for the new entrance. When you find the entrance hole they are using, you can block it with metal. Usually the best thing is bundled-up metal mesh on the inside of the hole to block access, and aluminum flashing nailed over the outside.

Raccoons are annoyingly persistent. If you block one hole, they will come back and make a new hole in another place. They consider it their den, not yours. Often the only option is to trap them and relocate them. Yes, people will tell you that it's cruel to relocate them because they may end up in another raccoon's territory and have to fight it out. After the first $1000 worth of damage you will be much less sympathetic.

Go up there and spray coyote urine everywhere. Do this once every season.

fdl wrote: ↑ These animals can scale walls , climb downspouts , etc. Smaller rodents like mice can even get in through weep holes. Cutting branches makes no difference.

I believe most animals getting into the attic usually squeeze in through damaged or loose soffits, but larger animals like a raccoon could probably pull up shingles and dig through if they really wanted to.

There are companies you can hire to seal off your home but they are very expensive.

I agree -I see squirrels and such easily get to the roof by any means.

I believe the previous owners of my house had issues with squirrels in the attic and they had it sealed off - unfortunately I don't really know any of the details. I should ask my neighbour - he's the one that told me about it.

Next-door neighbour has had squirrel/mice problem in attic for years. They were getting in through spaces around the soffit, so they had those sealed up with mesh wire. They still have a hedge cedar that provides an easy path to the roof. They hired a pest control company but they could only come a couple of times because they're overworked with other calls, left some ground-level live traps.

My next-door neighbour on the other side was feeding squirrels lots of peanuts every day, that's probably why the squirrels were in the area. They were also feeding wild birds and that attracted squirrels / rats / mice. Finally they got a clue and stopped the peanuts and reduced the bird feeding.

I had a squirrel in my attic a few years ago, might have got in by a roof vent that had a damaged screen. I removed 3 trees and hedges near my house to make it harder for them to get in. Squirrels are good climbers, once I saw one walking up the vinyl siding toward the roof. If I still had a cat I'm sure it would scare the squirrels away.

If you find the droppings in the attic you can determine the animal type by looking at the size/shape.
http://www.247wildlife.com/squirrelfeces.html

I agree. I have seen a whole raccoon family climbing down from my neighbor's roof through downspouts to the ground. So, even there is no tree or hedge, they could still get to the roof if they want............

fdl wrote: ↑ These animals can scale walls , climb downspouts , etc. Smaller rodents like mice can even get in through weep holes. Cutting branches makes no difference.

I believe most animals getting into the attic usually squeeze in through damaged or loose soffits, but larger animals like a raccoon could probably pull up shingles and dig through if they really wanted to.

There are companies you can hire to seal off your home but they are very expensive.

We recently had squirrel issues in the attic.

Found out they chewed through 3/4 plastic vents on the roof.

Replaced the vents with metal ones, no issues thus far.

Raccoons will peel back weak shingles (even strong ones), so not really much you can do.

enwhyRFD wrote: ↑ We recently had squirrel issues in the attic.

Found out they chewed through 3/4 plastic vents on the roof.

Replaced the vents with metal ones, no issues thus far.

Raccoons will peel back weak shingles (even strong ones), so not really much you can do.

Oh ya, anything plastic or wood is no problem for them.

enwhyRFD wrote: ↑ Replaced the vents with metal ones, no issues thus far.

Yes I remember now, that's what the previous owners did as well. No issues either and I have A LOT of squirrels and chipmunks.

We have wire mesh everywhere.

I have a old, cheap metal shed. I was in the shed today and noticed quite a bit of squirrel feces. There's not real effective way to close the gaps (other than getting a new shed). Any ideas on how to prevent this - can put something in there to deter them from entering or is this just one of those things that you can't really control?

Jazmina wrote: ↑ I have a old, cheap metal shed. I was in the shed today and noticed quite a bit of squirrel feces. There's not real effective way to close the gaps (other than getting a new shed). Any ideas on how to prevent this - can put something in there to deter them from entering or is this just one of those things that you can't really control?

More likely rats than squirrels at ground level. Is there anything that smells remotely like food in the shed?

Faith24 wrote: ↑ More likely rats than squirrels at ground level. Is there anything that smells remotely like food in the shed?

Nope not at all. I only have things like winter tires, lawn mower, wheel barrel, garden tools. However, have walnut and apples in my backyard. I also have a composter but it's at least 20ft from the shed.