bugs in tank?...

Hi everyone.

I've got a small 2 1/2 gallon tank with 1 Betta and an Ottocinclus. I've had
the betta since September & the Otto since November. I haven't had any
problems with them and their behaviour was always "normal".

Today I just noticed some very small whitish/translucent "bugs" moving
around on the glass walls and in the water. They remind me of newly hatched
brine shrimp (I used to have Sea Monkeys a long time ago. Ah, the
memories...) I also noticed what I think are small green worms too (Although
I couldn't see anything a few hours later). My fish are behaving normally,
and there is no sign of sickness or infection on their bodies. I haven't
tested the water yet (gotta get a new kit), but I have been away for the
last 2 weeks and a friend was taking care of them. I just changed the water
a couple of days ago. Could the bugs/worms be planarians? Anyone know what
could have caused this and what to do about them (if anything)?

Any suggestions/ideas would be great! Thanks guys!

Ciao.
Yaz.