You have probably seen some bugs crawling on the ground, flying through the air, or hanging out on trees. You can catch these bugs and sell them to Tom Nook, donate them to the museum, keep them in your house as pets, or just release them back into the wild.
How to get a net
To catch bugs in Animal Crossing: Wild World, you need to purchase a net from Tom Nook's store, or, alternatively, you can get a free net from Tortimer during the Bug Off Tournament. You can get more than one free net, even, as long as you don't have a net in your pockets when you talk to Tortimer. Learn how to get a Golden Bug Net.
How to use a net
The net is a fairly simple tool to use: when the net is still in your pockets, simply drag the net onto the picture of your person to equip it. Then, you can press A to swing the net. Alternatively, you can tap your person with the stylus while not viewing the contents of your pockets. This will also make your character swing the net.
The net will swing forward until it hits something, be it the ground, a tree, a body of water, or even a villager (although villagers tend to get mad at you if you hit them with your net).
If there is a bug in front of you, you can move your character into a position that will make the net land on the bug when you swing it. If you have aimed correctly, you will catch the bug when you swing the net. If you have not aimed correctly, the bug will probably get scared away. If you do not scare it away, but you didn't manage to catch it, then you can keep trying while the bug keeps walking or flying around.
A note about bugs
Where you can find bugs
There are many different types of bugs that you can find in Animal Crossing: Wild World. These different types of bugs have different types of habitats that they like to hang around in.
How to catch bugs on trees
A bug that hangs out on a tree will just be sitting right there on the tree trunk, maybe moving around a little bit, but generally just hanging out. Bugs that like trees will always be on the front of the trunk. They never hide on the back of the trunk where you can't see them.
It is fairly easy to catch a bug that lives on a tree. Just walk slowly up to the tree so that you are close to the tree trunk, but far enough away that you do not scare the bug away. Make sure to position yourself in such a way that the net will hit the tree trunk. If you are not close enough, the net will hit the ground, scaring away the bug. List of bugs
How to catch bugs that live on the water
I am pretty sure that there is only one type of bug in Animal Crossing: Wild World that lives on the water. To catch this type of bug, you need to stand at the edge of the water, as close as possible. Then, position yourself such that you are facing the bug. When the bug comes close to you, and you think that the net will land on the bug when you swing it, go ahead and swing the net. If you did it correctly, you will catch the bug. List of bugs
How to catch bugs that fly through the air
The difficult part about catching bugs that fly through the air is that you need to be quick when you swing the net. You have to swing the net at just the right moment, or the bug will fly out of range of the net before the net catches it. Just run after the bug, and swing the net when you think that you are positioned to be able to catch the bug when you swing the net. Sometimes flying bugs will fly over the surface of a body of water, becoming unreachable. This is only temporary, so just be patient and wait for the bug to hopefully come back. List of bugs
How to catch bugs that crawl on the ground
The method to catch a bug crawling on the ground is somewhat similar to the method for catching a flying bug, but it is a little bit less difficult than that. Just follow the crawling bug and swing your net when you think that the net will land on it and catch it. Crawling bugs tend to run away from where you are standing, so be careful not to make the bug run into a body of water. It can't avoid the water, so it might fall in and drown. List of bugs
How to catch bugs that crawl around on flowers
Occasionally you will find bugs that crawl on flowers. You actually will not encounter this type if there are no flowers in your town. To catch a bug that is crawling around on some flowers, just walk up to the flowers slowly (you can scare the bug away if you get too close, or walk too quickly), then position yourself to make the net fall on the bug. Just be aware that if your net lands directly on top of the flowers, you might destroy that bunch of flowers, so be careful. List of bugs
How to catch bugs that hide under rocks
There are some types of bugs that hide under rocks. Sometimes you don't know about them until you see a villager staring at the rock. The way to get a bug out from under a rock is to hit the rock with a hard object, like a shovel or an axe. The bug will jump out from under the rock and start crawling away. The tricky part here is that you must quickly switch to your net so that you can catch the bug. That task usually takes long enough that the bug might run off the screen or behind something, and it might disappear. Keep an eye on the bug to watch where it goes while you switch to the net. After that, now that the bug is scared aboveground, it is like catching a crawling bug. List of bugs
How to catch bugs that hide underground (but not under rocks)
There are some types of bugs that hide under the ground. The only ways to find out about those bugs is to either hear them making noise and figure out where they are hiding, or find a villager who is staring at the ground.
It can be difficult to figure out exactly where an underground bug is hiding, just based on sound. The key is that the sound will get louder the closer you are to the bug. So, to find where the bug is, if you hear the sound, just walk around until the sound is as loud as possible. If you are in the correct place, the sound gets quieter no matter which direction you walk in. That means that you are standing very close to where the bug is underground. Start digging holes with your shovel until you see the bug hop out. Then, don't bother with covering up the hole; it takes too long. Just switch to your net as quickly as you can while watching the upper screen to see where the bug goes, then run after the bug and catch it like you would any other crawling bug. List of bugs
How to catch bugs that hide in trees
For bugs that hide in trees, the only ways to know that the bug is there are to either shake the tree and see it come out, or see a villager staring at the tree. For bees, please read the separate article about catching bees (which I have not written yet). For other tree-based bugs, just equip your net as quickly as possible and swing it at the bug. List of bugs