foam in fish bowl

Question
what is the foamy substance in my fish bowl.  I have one chinese fighting fish that I just got last week.  But today I find all this foam clusters at the top of the bowl.
The fish seems fine, but I am puzzled.

Answer
Good evening Debra,

Your betta (actually a Siamese fighting fish) has built a bubblenest! This is perfectly normal and an indication that it is healthy and happy. You can read more about it here:
http://www.healthybetta.com/articles/New%20To%20Bettas/bubblenest.html

Hopefully you are regularly changing the water, 50% twice a week would be my recommendation. Add dechlorinator each time, Prime 50 mL dropper bottle is my choice, since 3 drops per gallon is all that's required. If your room temperature never drops below the high 70s, it might be all right, but I recommend a bowl heater such as the 7.5 watt heater made by Hydor, available at Petsmart. I also recommend you add some gravel to the tank instead of glass chips - this boosts biological filtration, since beneficial bacteria cannot take hold on glass surfaces as well as they can on porous surfaces such as river rock or gravel.

I hope that helps! Read more about betta care right here:
http://www.bettatalk.com

Take care,
Nicole