If you’re already interested in flies, check out how they behave in nature. They can be quite territorial about their leaf or stick and fights between these agile little beasts are fascinating to watch (extremely quickly orbiting each other).
How many flies are in my apartment?
31–40 of 158 posts
Re: How many flies are in my apartment?
#32Earlier quoted context omitted.
Flies are small... you'd need a lot of light, multiple angles and good cameras/lenses to decently illuminate the flies, which has the problem that all the light will only attract more flies.
Is this really true? I mean we've had tech like Hawk-Eye[0] for a couple of decades now. Surely we cameras good enough for fly tracking technology in 2021? [0] https://en.wikipedia.org/wiki/Hawk-Eye
That camera system tracks a single, largish object in perfect lighting.
I think the biggest problem with insect tracking is focus: They are so small that they can only be recognized if they are perfectly in focus, so you probably can't track them in 3D volumes.
Maybe you could track them with clever lighting tricks. Eg. illuminate room with very bright light coming from the side, with a black wall, so that mosquitos show up as bright spots in the video.
Re: How many flies are in my apartment?
#33Earlier quoted context omitted.
This is the norm in the south asian country I come from. But ever since I moved to the EU, there have been no nets, then again there are noticeably fewer flies here too.
Dont the windows have screens? In the US pretty much every window has a permanent screen outside the panel for this purpose...just assumed it was the same in europe
Not in south of Europe unless is a mosquito disco location. One of the main purposes of windows is to see out. The more transparent, the better.
Another factor is the light level. If you have a lot of days with rain or low light, like UK or many other places have, nets reduce even more the level of light entering in the house. Lacking of a lot of the dangerous mosquito borne diseases than tropical places have, the cons weight more than the pros. Would be seen as a better deal in California for example, where the extra shadow is welcomed.
And finally there is some inertia provided by cultural factors. For Dutch allowing everybody to see your room by default (don't have anything to hide here) is a cultural post-war thing also.
Re: How many flies are in my apartment?
#34All these models ignore how insects actually zero in on a smell. For a fly outside, the source of the smell is the gap in the window. What looks like random direction changes is actually a search pattern for that source.
Re: How many flies are in my apartment?
#35All these models ignore how insects actually zero in on a smell. For a fly outside, the source of the smell is the gap in the window. What looks like random direction changes is actually a search pattern for that source.
Slightly related: Anemotaxis https://www.youtube.com/watch?v=hIqmIQbQkW8
Re: How many flies are in my apartment?
#36Is it better to leave windows open so flies can escape or closed so they never come in?
If your windows open outwards, windows open, no contest.
If however they open inwards like mine, open sounds good in theory... but you may end up more frustrated at idiotic flies buzztapping against the interior side of the glass time and time again, rather than flying around it and getting the hell out. Might as well keep the windows closed and accept the flies are here to stay rather than living in false hope while new ones keep buzzing in.
Re: How many flies are in my apartment?
#37This would be an interesting thing to prove with OpenCV
Flies are small... you'd need a lot of light, multiple angles and good cameras/lenses to decently illuminate the flies, which has the problem that all the light will only attract more flies.
I think it would be fine if you tracked only the flies that entered or exited through the small hole in the wall, ie not tracking the whole room just a tiny corridor.
So yes, you know the delta-fly(er) but not the number of flies.
Re: How many flies are in my apartment?
#38Earlier quoted context omitted.
It's becoming increasingly common where I live (Poland). We've installed nets in our last apartment, and the current one came with them already in place. There may not be that many flies in the EU as there are in South Asia, but there's enough of them to be annoying. Then there are mosquitoes, moths, wasps, bees - and the very bugs I've been installing these nets against - hornets . Before the net, we'd get 3-5 horne…
Okay, first of all, tell me more about this flamethrower. Also, when you say "nets", do you mean "screens", ie on the windows?
> Okay, first of all, tell me more about this flamethrower.
Just a lighter, a spray can, and steady hands. I know you're probably disappointed, but simplest solutions do work best :).
(To be absolutely clear: I only use this against wasps and hornets, and only in situations where there's no safe way of shooing them back out through a window.)
Operation: hold the lighter in front of you, light the flame, spray above it. Aim for sub-second bursts of flame - you don't want anything in the room to heat up. Never let the flame come close to any highly flammable surface (like drapes, or aforementioned mosquito net).
Tactics: against hornets and wasps, I shoot either below it, or at it directly. Shooting below, the rising hot air will confuse the bug, possibly stun it for a moment. Shooting at it, a sub-second burst is enough to burn off is wings, at which point you can finish it off using your favorite percussive maintenance tool.
Equipment considerations:
- I tend to use cheap, widely available flint lighters. I have experimented with gasoline and butane (high-pressure) lighters before, but IIRC, they didn't work well.
- For fuel, I use a deodorant. In the past, I've also used a hair spray - it's a good choice, because it enables a third mode of operation: cold mode. Because hair spray is viscous, hitting a bug with it is likely to clog its breathing apparatus and glue its wings, allowing you to safely apply the killing blow. I found it useful in a tent[0], where you absolutely do not want to play with an open flame of any kind. Anyway, any kind of spray with a flammable mixture will work, but pay attention to the possible combustion products. I do not recommend going for pressurized butane gas directly - it won't combust fully, and you'll be cleaning soot from every solid surface near you (ask me how I know).
I've been thinking about building/3D-printing a mount to operate the flamethrower single-handed, but to be honest, using two hands gives greater control, and the optimal distance between the lighter and the spray can varies with the type of spray can and environmental conditions.
> Also, when you say "nets", do you mean "screens", ie on the windows?
Yes. I buy a box with a fine mesh net, which I cut down to size and attach to the inside of the window using provided mounting strips (adhesive on the window frame size, velcro on the net side). We call this "moskitiera" (mosquito net). For balcony doors, there are variants with the net split in half and held together with magnets - so you can walk through it, and it'll close behind you.
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[0] - I was once on a two-week camping trip where we were constantly assaulted by swarms of wasps. We didn't know until later that it was because there was a hive under the building near our site. The organizers of that camp actually funded me a supply of hair spray, and designated me as the camp's exterminator. The "cold mode" was useful for cleaning out tents every couple hours. After we left, the owners of the building decided it's too much hassle to clear out the hive, and burned the building down.
Re: How many flies are in my apartment?
#39All these models ignore how insects actually zero in on a smell. For a fly outside, the source of the smell is the gap in the window. What looks like random direction changes is actually a search pattern for that source.
Very good point -- and that's why they find their way inside so easily, but look really dumb trying to find their way out.
Same principle behind a DIY fruit fly trap (glass of juice with a plastic cover with a few holes poked in it).
Re: How many flies are in my apartment?
#40In my statistics class we were taught a technique for estimating the number of flies in a barn. You capture a fixed size sample of flies, e.g. 100, and give them each a little white dot on the back, then release them all back in the barn. Leave them to mingle for a while, then capture another fixed number of flies, e.g. 100. If 5 of them have a white dot on them, then you estimate that the 100 flies you captured originally and marked make up 5% of the total population, meaning your estimate of the total population must be 2000 flies.