Thank you for your patience - we've reached-out to one of our wildlife specialists for feedback on which animal left this scat. Meanwhile, scat ID keys suggest this may be raccoon:

https://icwdm.org/identification/inspection/brown-or-black-droppings/#Tubular

https://lancaster.unl.edu/hort/mastergardener/resources/Wildlife-Scat%20ID%20KEY.pdf

Miri

Hello there,
I agree with Mira's assessment.  This looks like a raccoon latrine. Raccoons like to keep their waste in a designated area and will use the same spot multiple times. It looks like there were two defecation events on the same spot given the two different colors.  Raccoon scat oftentimes has seeds visible in it like in your photo and they oftentimes defecate in obvious open areas like you have here.  

The most comprehensive recommendations on removal of the scat are from the CDC at this link:
https://www.cdc.gov/parasites/baylisascaris/resources/raccoonlatrines.pdf

To prevent them from continuing to use the area, after you clean it up try to place something from your patio in the area to block the spot, or put some plastic grocery bags down on that location (they don't usually like the sound of crinkling plastic) after cleanup to deter raccoons from wanting to use the area. They usually relocate their latrine area pretty easily.

Best,

Luke Macaulay

University of Maryland Extension

Wildlife Management Specialist

You are welcome.