We humans share the planet with a pretty large number of animals. Some of them are super adorable and let us put jackets on them or allow themselves to be instagrammed on a daily basis. Others are so majestic and beautiful we catch them and put them on display behind glass and bars. Still more of them can be turned into clothes and spicy, crispy sandwiches. But... then there are the ones that come onto our property without invitation, like they own the place. And for some reason when you call 9-11 the cops tell you to just kill the spider yourself.
Do you ever wonder what the most common un-invited animal in your home is? I do. These are the kinds of things that keep me up at night. I know this list can't be exhaustive because there really are so many animals that share our homes that we don't even see like bedbugs and lice... so I'm focusing on the big ones. And, heads-up, my list is focused on North America because that's the continent I live on. Vote up the animals that you have encountered on your property.
If you live in the northern parts of North America you may not see these little invasives, but if you live in the South or any part of the world that is even a little bit warm - meet the Argentine ant.
This tiny little lady is originally from Argentina and is the success/devastation story of the insect world. They have spread to every continent except Antarctica. They have been so successful in their world domination partly because different nests - when they spread into each others' territories - seldom attacking or competing with each other, unlike most other ants. Thus, in most of their introduced range, they form supercolonies.
You will see them, when they come into your home (if they do at all), as teeny-tiny little black ants that congregate around water sources like your kitchen sink or your bathtub. Interestingly, you can sometimes see queens foraging alongside the workers. They will come inside when it gets particularly hot or dry outside -- or super rainy. When you do see the scouts, try to cut off their foraging trails to keep them from finding whatever treasure they are looking for. If a scout never makes it back to the colony, the rest of them might not end up marching into your home.
There is something naturally repulsive about earwigs... probably that chitinous shiny look they have and those pincer-looking things on their butt. Earwigs are medium-sized insects with flat bodies and are usually black or brown, some with stripes or reddish coloring. There are around 22 different kinds in the US, but it is unlikely that anyone wants to collect them all like trading cards. The hard pincher-looking forceps they have are used as a defense mechanism and weirdly, they also have wings but rarely fly. They tend to be nocturnal, feeling on other insects as well as organic materials like moss, fungus and lichen. They also eat decaying organics as well as food you might have in your kitchen.
Weird fact about the earwig is that females of some of the species actually care for their young -- watching over the eggs and even feeding the nymphs after they hatch. This is super-unusual in the insect world.
Of note, and important to know, earwigs do NOT crawl in people's ears. This silly myth has been impossible for them to shake for some reason. You would think that after what must be thousands of years of sharing our habitations with these things, we would have noticed by now that none of them have crawled in our ears.
(Domestic House Spider in Europe)
There are actually a number of spiders that get this general 'house spider' term applied to them. Most people are too busy screaming and making the 'kill it with fire' joke to suss out the difference. This particular pal is very common world-wide. It is believed that it was originally from Europe and imported here when the New World was colonized.
The coloring of this guy is typically dark orange to brown/beige/greige, with striped legs and two dull, black, longwise stripes on the body. They very rarely bite as they are non-agressive. They build a funnel web, usually in a corner and sit at the smaller back of the funnel, waiting for prey to disturb the cone which is when they rush out and grab their meal. The males tend to just roam around the house, moving quickly if they feel threatened. If you catch them and toss them outside because you are feeling non-murderous, they will very likely die anyway unless you live in a warm climate. They are good pest-killers, however, and if they build in a corner of your home that is mostly unused, it's not a bad idea to leave them to their work.
If there was list ranking the most annoying household pests, I think this little a-hole would be #1 with very little competition. House flies are major carriers of disease and can infest all types of homes. They are attracted anything edible, including your food, your animal's food, garbage and feces. Once you see an adult fly you already have a problem. They live about 30 days and quickly mature from an egg to an adult. They breed in moist decaying vegetable matter like an uncovered garbage can or a compost bin.
Once in your house, house flies can be found resting on walls, floors or ceilings.
Outside, at night, they prefer to rest near food sources approx. 5 to 15 feet off the ground.