Something is crawling in my Aquarium!

Question
I am trying to find out what this is.  It doesn't look like a mosquito larvae, but I may be wrong.  I have a 10 gallon tank with a few guppies.  One of my females had babies so I put a breeders net in there to keep them safe.  It has been in there for only a week and a half, but now I have these black things crawling all over the top of it.  They don't appear to like being submerged.  They remind me of a caterpillar because they inch around the same way.  They don't swim like mosquito larvae do.  Just crawl around.  The bigger one that I found
(about 1/4 of an inch) appears to have tiny hairs all over its body.  If I dislodge one from the net, it sinks straight to the bottom (where my adult guppies gobble them up).  My aquarium has a hood and a light.  Can you identify them or direct me to someone who might be able to???  
I change the water at least once a week and I am very observant.  I have never noticed these things until today. I just want to make sure they are not going to hurt my fish.

Thanks.


Answer
Hi Gwen;

Sounds like one of the numerous creatures found in pond and lake areas. Some insect has probably found your tank a perfect place to lay eggs. Since the adult fish gobble them up I don't think they are harmful. I would just let more of them fall in the tank for them to eat. It's perfectly healthy for them.

At Your Service;
Chris Robbins