Bugs in Freshwater tank. HELP PLEASE!

Question
These bugs are on the sides of my tank. When I reach in to clean them up or          , they jump. These bugs are black w/6 legs and are very tiny. I have a 35 gallon tank with a few smalls plants and 3 sharks of some sort and 8 guppies and a golden loach. My tank has two 50 gallon filters and 25% of the water is changed every 2 weeks. Please Help, 1 of my fish has died since I noticed the bugs.

Answer
That's very odd. Would you happen to have a pictures you can get to show me. I have no heard of very many aquatic bugs that get into aquariums much. Is there a chance they could have come in on your plants at all? did you just get the plants recently. Are there too many you can get them out with your hands , or doing water changes.  I would suggest water changes every week aswell.

I need more information to answer this.