No, probably not (you can relax now). There are many reasons a bat might be visible during the day, but you are probably seeing a tired, lost, or generally confused bat taking a rest. It will most likely be on its way when the evening comes. There is a ton of misinformation about this on the internet. Seeing a bat during the day DOES NOT mean it has rabies. Though bats are often associated with rabies, the disease is actually quite rare among bats. If you do spot a bat on a tree or bush during the day, please let me know using the bat sighting form, it is very helpful data!
A bat on the ground is in a bad situation. Bats are not able to take off from the ground, so the bat will be stuck there unless someone helps it. You have several options to help:
Call Wild Bird Fund, (646) 306-2862
Wild Bird Fund is a wildlife rehabilitation center. They are unable to take bats, BUT they can put you in touch with a licensed wildlife rehabilitation specialist who may be able to help
Call NYC Animal Care Centers via 311
ACC will take reports of injured bats, but they may not be as helpful as Wild Bird Fund. Simply dial 311 to file the report
Help the Bat Yourself (NOT RECOMMENDED, READ THOROUGHLY BEFORE ATTEMPTING)
This option comes with very real personal risk and involves handling the bat. IF YOU DO NOT FEEL COMFORTABLE DOING THIS, IT IS OK, PLEASE DO NOT FORCE YOURSELF. Handling a bat is dangerous and you should NEVER do it outside of this situation. Only do this if you have something substantial to cover your hands with (heavy gloves or garment you can wrap around them) and, if you are far from any trees, something to place the bat in (grocery bag or paper bag are ideal, do not use plastic bags)
Step 1 - Thoroughly cover your hands before picking the bat up. It WILL try to bite you, a lot.
Step 2 - Carefully move the bat from the ground into your protected hand. Approach the bat from behind and try to get the bats body and both wings all securely within your hand. Always use a light grip. The bat will begin biting at your hands pretty much immediately, don't panic (also don't take it personally) this is just what they do
Avoid stretching, bending, or otherwise contorting the bat's wings, they are very delicate
Step 3 - If there are trees near by, carry the bat to a tree and attempt to place it on the tree bark or a low-hanging limb. The bat should readily grab on to the tree. If there are no trees nearby but you are able to walk to somewhere close that does have trees, you can place the bat in a container for transportation. Paper bags or grocery bags are ideal, just avoid plastic bags. If you are able to move the bat to a tree successfully, congrats, you saved a bat! If the bat will not attach to the tree, call Wild Bird Fund or NYC ACC (info above)
IMPORTANT - IF THE BATS TEETH MAKE ANY CONTACT WITH YOUR SKIN, DIAL 911 IMMEDIATELY. A HOSPITAL VISIT IS 100% MANDATORY FOR ANYONE BITTEN BY A BAT
Just to emphasize, this is risky and I do not advise doing it if there are any other options available. Unfortunately there are not many resources for injured bats in the city, so I am providing these instructions for emergency situations in which there are no alternatives.