It's the second City Nature Challenge for Philadelphia and the fifth globally, and the original idea was to send people out in nature to document as many species as possible, in each city, and then see who recorded the most.
But Philadelphia organizer Navin Sasikumar said looking locally — really locally — is this year's plan.
"There's a lot of animals living inside your house. You can find spiders in corners and stuff like that. And this year, we are really encouraging people to go out, after observing all safety precautions, of course, and looking for things on their own or in the family unit,” he said.
And he said if you don't know what you are seeing, there's an app for that: iNaturalist.
"And you take a photo with the app and upload it, and even if you don't know what it is, other people will come along and ID it,” he explained.
He said security cameras are also helpful.
"For example, I have a fox that occasionally comes in front of my front door camera, so I added that as an observation as well,” he said.
The City Nature Challenge runs from April 24 through April 27.
April 26 is Moth Night, and Sasikumar said people are urged to turn on their outside light on the porch or balcony, and see what kind of winged creatures show up.