Bugs Found Near Water: 3 Types and What to Do
Bugs Found Near Water are one of the most common identification questions we get. Here are 3 you are likely to see.
Quick list
How to narrow it down
Narrow it down with three quick checks. Count the legs: insects have six, spiders and ticks have eight, and centipedes and millipedes have many more. Check for wings, even folded ones. Then compare size against a coin: a US penny is 19 mm across. Our bug identifier tool does this filtering for you.
The 3 bugs
Mosquito
MosquitoCulicidae (e.g. Aedes albopictus)A small, slender fly whose females bite to take blood for egg production. The Asian tiger mosquito is black with white stripes and bites aggressively during the day.
Tell-tale sign: Long, needle-like mouthpart (proboscis). Risk: Mosquito bites itch and, depending on the region, can transmit West Nile, dengue and other viruses.
Horse Fly
Horse FlyTabanus spp.A large, stout fly with huge eyes that pursues people, horses and cattle for blood. Females slice skin with blade-like mouthparts, causing a sharp, painful bite.
Tell-tale sign: Large, heavy body with very large, often iridescent eyes. Risk: Horse fly bites are painful and can swell; they rarely transmit disease to people in the US.
Common Green Darner
Common Green DarnerAnax juniusA large dragonfly with a bright green thorax and, in males, a blue abdomen. It patrols ponds and fields catching mosquitoes and other flying insects.
Tell-tale sign: Green thorax with a bull's-eye mark on the face. Risk: Dragonflies can't sting and almost never bite people.
Which ones should you worry about?
2 of the 3 bugs in this guide can bite or sting. The ones to take seriously are mosquito. The rest are harmless or simply a nuisance.
Comparison at a glance
| Mosquito | Horse Fly | Common Green Darner | |
|---|---|---|---|
| Group | Flies & Mosquitoes | Flies & Mosquitoes | Other Insects |
| Scientific name | Culicidae (e.g. Aedes albopictus) | Tabanus spp. | Anax junius |
| Size | 3–6 mm | 10–30 mm | 68–80 mm |
| Colors | Black, White and Gray | Black, Brown and Gray | Green and Blue |
| Legs | 6 legs | 6 legs | 6 legs |
| Wings | Yes | Yes | Yes |
| Bites or stings | Bites | Bites | No |
| Risk | Health risk | Can bite or sting | Harmless |
| Key feature | Long, needle-like mouthpart (proboscis) | Large, heavy body with very large, often iridescent eyes | Green thorax with a bull's-eye mark on the face |
Frequently asked questions
What is the most common one?
Among the bugs in this guide, the mosquito and horse fly are the ones people ask about most.
Which of these are dangerous?
Mosquito can be medically significant.
How can I identify a bug I found?
Use the free bug identifier tool: choose the number of legs, wings, main color, size and where you found it, and it will list the closest matches.