Bugs? yuck

[absolom]

I changed the filter in my freshwater tank today and found little bugs crawling around in it. I haven't added anything new to my tank in about 2 years. I found a question on another forum and they said they might be copepods but it didn't give much information. Do I have an infestation of some kind? How did I get it? Where did they come from? When I put the new filter in the aquarium and checked 8 hours later there was nothing. Do I need a can of aquarium "Raid"?

25 gallon fresh water tank
1 bamboo shrimp
1 red gourami
3 silver danios
No live plants
Eclipse in-hood Filter system with charcoal insert and bio-wheel

Thank you if you can help!

 

[Mebbid]

Without a picture, it's impossible to tell you what you have.

However, if you keep a very watchful eye I bet you would see different types of tiny worms crawling around in the substrate too. Our tanks are full of weird little bugs and critters most of which make great fish food. I wouldn't worry about it.