Thanks for your care of this Squirrel! Please read the Henry's Guide! (
https://www.henryspets.com/1-baby-squirrel-care-guide/ )
Squirrels love nuts and fruits they can and will develop a very serous disease called Metabolic Bone Disease (MBD) if they are permitted this type of diet. This results from an absolute deficiency in Elemental Calcium or from excessive phosphorus intake. It is usually both. The nuts and fruit diet WILL result in a depletion of Calcium and development of MBD. Many of us who have been at the intake end of Squirrel care have seen one or more cases of MBD. This results in fractures, decreased appetite, neurologic problems including seizures and oftentimes, death! Also, it is very painful. Captive Squirrels including the babies that are being raised for eventual release are given Rodent Blocks as their primary diet. This should comprise at least 80% of a captive Squirrel's nutritional intake. The remainder should be healthy vegetables, healthy fruits and natural foods! Here is a link to Henry's Healthy Diet Pyramid: (
https://henryspets.com/healthy-diet-for-pet-squirrels/ ) and to go "Full Henry's with you, here is a link to Henry's excellent MBD information pages: (
https://www.henryspets.com/what-is-m...-bone-disease/ )
I would suggest ordering Henry's Picky Blocks immediately. The maximum to be eaten would be 3 daily and if your Squirrel consumed 2 full blocks, that would be enough. The remainder of nutrition would be from the Healthy foods. When the Squirrel is eating Blocks regularly, it is fine to give a rare treat of a nut such as a raw in-shell Pecan. Other blocks are available but they are not as tasty as Henry's. Options include Envigo 2018 also called Harlan/Teklad (this is what I use as a base for my Squirrel Blocks) and can be ordered in reasonable amounts from eBay. Ecosandy is the seller I use on eBay for the Envigo Blocks.
Another option is Mazuri Rat and Mouse Diet and these are hard extruded Blocks similar to the Envigo Blocks and these are available in many local Pet stores such as Petco. I would recommend going this way as you can get these Blocks immediately without having to wait for shipping!
Please post the photos preferably with a ruler or some reference for size determination.
Thanks again for caring for this little Squirrel!
Regards,
SamtheSquirrel