Depending where you live in the world, your pond will have different critters that can been seen if you look close.  Here are some from Britain.
 
Summer is a time to leave your pond and its wildlife in peace. However, by looking at your pond at night, you might be surprised at what creatures come out when the sun goes down.
You’ll be surprised how much wildlife is attracted to your pond. Watching what appears can also be a nice study of how and why animals disperse. Ponds, whether natural or man-made, are transient and often isolated habitats and many animals are well adapted to seeking them out.
 
https://www.countryfile.com/wildlife/insects-invertebrates/how-to-identi...