Actually it's better to look for these guys at night. There are a variety of creatures that come out at night in our tanks that you may not see during the day.
If you have a red light you can take a look at your tank without frightening them. You may have a headlamp or flashlight that has a red light. A buddy of mine used the tail light from his bicycle to view his tank at night. A Phillips Hue bulb on a lamp set to red may work. Hey it's almost Christmas ask your wife if she has a red glass ornament or clear red giftbag paper you can shine a flashlight through.
It's amazing what you might see. Please report back on what you may find.