If you are a regular reader, you probably have a commute which keeps you away from home for a good part of the day. For those of us with dogs and/or cats, this can be tough on our pets.

A popular solution is the pet door. They allow our pets to get out, get some fresh air - and for dogs, it’s a welcome bathroom break. Anyone who has a pet door can probably attest to the fact that their pets love it, and use them all the time - well, at least mine do.

I caught this guy coming through the cat door to eat cat food at least 6 times the first night I setup the motion capture software.

However, pet doors have a few drawbacks…

First, unless you get a good quality pet door and install it properly, you’re probably going to lose some heat through it, or even get a nasty draft. As for looks, they aren’t exactly aesthetically pleasing - especially a dog door which has seen it day.

The biggest problem by far is that pet doors do not just work for your pets - but for pretty much any animal - and in the case of a large dog door - they work for people too.

From experience, I can tell you that the #1 offender of pet door breach is THE RACCOON. I have had cat doors on 3 different homes, on both coasts, and although it usually take a few months or even a few years, a raccoon will inevitably find his way through that door. Once he does - believe me - he will probably use it more than your pets! Even a relatively large raccoon can slip through a tiny cat door with surprising ease.

Worst of all, it will probably be a while before you know it. I can easily hear my cat going in and out the door down the hall, but one time I caught a raccoon red-handed, I had barely heard the door move at all (although it freaked me out when I realized my cat was fast asleep at the foot of my bed).

And don’t expect your pets to alert you either. Cats and raccoon have some sort of interspecies détente which insists they let each other pass without letting out a peep. Meanwhile, while my Lab will wake me up in the middle of the night to let me know he sees a raccoon out the window on the front lawn, for some reason he is oblivious to one in the next room. Your mileage may vary however, as I have had to help break up a nasty fight between a raccoon and an Akida - its not pretty.

There are some dead giveaways of raccoon visits however if you know what to look for.

The easiest one is if the raccoon has been eating your cat or dog’s food. Once inside raccoons will go for the low-hanging fruit, and this usually equates to pet food. If there is a bowl of kibble on the floor he typically isn’t going to push his luck by opening your cabinets and sorting through your kitchen trash.

Also check that their food area isn’t unusually dirty. As filthy as they may seem, raccoons have a fetish about washing their food, especially when it’s convenient - nothing is more convenient than a water dish. This makes a mess.

So, check out your pets food area - are they eating more food then normal? Is their water inexplicably filthy or have food in it? Is the area around their eating area covered in muddy pawprints?

Then Congratulations, you have a raccoon!

Another thing to check for is to pay attention when you hear the pet door being used and where your pets are when you hear it. This can be a rather startling moment when an otherwise benign sound suddenly takes on a decidedly sinister air - like when you find out the killer is calling from inside the house.

Another detection method I have never tried is to sprinkle a light layer of flour around the pet door zone, which should allow you to easily identify any foreign pawprints.

If your experiences are anything like mine, when you finally catch the culprit you will reflect back on several hints that suddenly seem obvious in hindsight.

For example, last night I caught a raccoon entering our latest home for the first time, although I had plenty of clues leading up to it.

This time, the discovery was quite intimate - the cat door is next to my side of the bed, and I heard it being used. As I opened my eyes slightly to look, I realized it was far too big to be my cat - just a black mass glowing in moonlight with a big bushy tail 2 feet away. We got up to shoo it out, and it was my wife who caught it on the kitchen counter and sent it scurrying for the exit with a scream.

I admittedly had a lot of advance warning the prior week or so:

• I had noticed my cat carefully sniffing the dog bowl and his cans of food, as if an animal had been there (duh!).
• Twice our dog was inexplicitly outside scratching to be let in, he wouldn’t use his dog door.
• I thought I had heard the dog door being used while I was fairly certain the dog was asleep in another room
• The dog woke me at 2AM to let me know there was a raccoon on the front yard
• One night I got up because I heard a noise, and although I found nothing, I heard a raccoon chattering an alert outside the dog door.

I know, that all sounds pretty obvious, but when it comes to pet doors I have a high degree of tolerance/denial as I really like my pets being able to have them. I also like to kid myself that its an isolated event, although I certainly know better.

On another occasion, I had to go all James Bond to figure it out. I downloaded some motion-detecting software for my laptop, plugged in a webcam, and pointed it at the cat food area. The next morning, not only did I have ample footage of what seemed like multiple raccoons serially tearing through a massive bowl of Eukanuba, but they would not eat it all at once - they came in shifts all night long - 5 or 6 times or more!

OK, so now we know what to look for - now what?

First off, you need to deny entry, which means closing the door with a cover or lock. This is going to probably translate to your pets bugging you incessantly to let them out at all hours - don’t cave - let them out as needed but don’t try to replace the cat door by letting them in and out at will. The sooner they understand the new ground rules the better.

Also, you should keep the entry completely locked down for at least three weeks, to let the raccoons know that the Inn is permanently closed. If nothing else, this will probably take you off their regular late-night feeding route for the time being. However, they will be back, so don’t think a few nights or even weeks later a couple of coon-less nights means you’ve won.

You might be inclined to install a floodlight or motion-trigged flood outside near the cat door - I can personally attest that this is completely useless. Another solution which has not worked for me is to locate the pet door in a fenced-in yard (believe me - raccoons find fences humorous).

Trapping and remote relocation is one option we’ve looked into - but make sure to check your local laws first - I think California, for example, specifically outlaws this. If you do, make sure you drive FAR away - they will make an effort to get home.

Personally I would never kill a raccoon just for my own convenience. However, if you are considering this (maybe its more of a safety issue for your family, for example), keep in mind that raccoons don’t always feed alone, so you might literally wind up playing whack-a-mole over a period of time.

Other suggestions include spraying the area outside with something which will offend raccoons but not your pets, like powdered fox urine. I would only consider this a way to augment other techniques and not a standalone solution.

Also, keep food away from the pet door. Obviously. If you’re door borders a kitchen or a pet food area, you are just asking for it.

Some owners have reported success with permanently installing a small AM radio tuned quietly near the pet door - any evidence of alert human beings is a no-go for raccoons.

Next on the list is to replace the pet door with an electronic model. Traditionally, these units feature a magnet which attaches to your pet’s collar. The magnet acts as a passive key, unlocking and relocking the pet door when your pet passes through it. Animals without a magnet don’t get in. However, there are some issues to consider:

• Smart raccoons can get through some lesser models by getting their claw under the sliding panel and lifting it up.

• Some models can be opened by any magnetic force, which is more of a human security issue to remember, especially for larger dog doors.

• They are expensive and typically require a much more significant installation procedure.

There is a newer model coming out with RFID technology which promises to be the most secure door yet. An RFID chip is attached to the pets collar, which actually performs a mathematical exchange with the pet door to open it. Only assigned chips will open the door. Its the same technology that sets off the alarm when you walk out of WalMart with a video game down your pants. It is also not ‘liftable’ by prying claws.

Finally, there is one of the most obvious and probably effective methods of all.

Just lock the pet door at night.

Raccoons are nocturnal animals - I have never seen a raccoon in broad daylight, although I can tell you that they will breach a pet door at early dusk and late into the dawn - but if the sun is fully up, you’re probably good. If the pet door is in the room where you spend your time in the evening before going to bed, like the living room, the raccoon usually wont venture in while you’re up either.

Now that we have thoroughly examined the issue of raccoons, I have to mention another hazard of pet doors as well - particularly if you have a cat - and thats gifts of prey. Personally, I have a lot more tolerance for this then my wife does, but it is indeed a pain in the ass.

My cat keeps an eye on his gift of prey. No one likes being woken up at 2 AM to The Tom and Jerry Show, but sometimes I have to admit it is genuinely funny and entertaining.

Usually during the spring and early summer, and almost always at night, my cat will frequently bring a guest into our home through his cat door, including:

• Mice
• Rats
• Birds
• Chipmunks
• Small Squirrels

Amazingly, they are almost never dead or seriously injured. I think he is so excited when he catches one (he’s crosseyed), that he just immediately runs inside with it before he has a chance to bat it around. Although I appreciate him not killing stuff, this leaves me in the role of unwilling third-shift exterminator, which is a multi-step job:

1. CONTAINMENT. I cannot stress this enough. You need to figure out what room the mouse (or whatever) is in (usually the room your cat is in), and seal it off. My cat likes to bring stuff in the master bath, which is perfect since its small and doesn’t have much of anywhere to hide.

2. GET THE CAT OUT. The cat is just going to complicate things, so remove him from the room and shut the door quickly behind.

3. LOCATE. Amazingly, I have never lost track of my cat’s catches. It would be so easy for them to run or fly to some hiding area, but usually once I get the cat out they are usually in a state of shock and just kind of freeze. Once it gets out of your sight, you have a MUCH bigger problem on your hands, as you may not find it for days.

4. CAPTURE. My favorite method, especially for rodents, is to throw a bath towel on them and bunch it all up so that they are trapped in the towel. This protects the rodent - and your hands from getting bit. I have also used paper bags and small boxes to create a convenient hiding place near the rodent which they immediately run into. One mouse was hiding in a sneaker which made things easy.

In another case, a baby squirrel was hiding somewhere I could see but couldn’t get to. This is a rare case where I actually went and got the cat and put him in there to flush it out, then I went back to #2.

5. RELEASE. Take the visitor outside, and out of the view of your cat (this is important). If it is healthy just throw it out the door and it will take care of getting the hell away from your house fast. If it is injured and can’t run or fly, you have a decision to make - either walk it out to some wooded area away from the house to give it a fighting chance to recover, or put it out of its misery and throw it away (don’t leave the carcass where your cat can find it!). Generally this will depend on how bad the wounds are.

Probably the greatest length I have gone to was the case of a chipmunk which hid under the bottom of the bathroom cabinet. I couldn’t even see in there, much less get him out, and neither could the cat. In this case, I put some glue traps just outside the cabinet and kept the bathroom door closed for two days, checking the traps every few hours. Eventually, he came out for the peanut bait and got stuck. This was my first experience with glue traps, and realized that although they sound humane there is no simple method of releasing the animal from the trap, and it isn’t intended. Some animals will also chew off their limbs to free themselves.

I had the afternoon to myself and the wife wasn’t around, so I brought the trap, chipmunk, and a bottle of vegetable oil to the backyard where I slowly and patiently removed the chipmunk from the glue limb by limb. It took a long time, and we sacrificed most of his tail in the process, but I don’t think he minded at all.

I do, however, wonder how long a small, injured, starving, dehydrated, frightened and exhausted chipmunk, completely marinated in cooking oil, would survive in the Connecticut suburban wilderness.

I do know for sure, however, that he appreciated the second chance.