Place a variety of food for the gray squirrels to eat and record which one most of the squirrels prefer to the least. Also change around what food is given to the squirrels over a period of time. Try also giving them their favorite foods only, but repeatedly. Then replace this food with the food that they didn't like as much. Observe if there is any change in their food selection.
Nuts are a favorite food of gray squirrels, and they will use their agility and intelligence to find them. Make an obstacle course that the squirrels can attempt, with a bowl of nuts placed at the end of the structure. First, put a pole in the ground with a wooden platform attached at the top. Thus should be the first obstacle for the squirrel to climb. Next, attach a small plastic tunnel to the platform for the gray squirrel to run through. There should then be attached to the tunnel another platform, with another tunnel attached to this. The bowl of nuts should be placed at the end of this tunnel.
For regular squirrel visitors to a garden, make slight changes to the environment. Change the garden furniture around, or remove it. Put new garden statues down and remove existing ones. Observe how gray squirrels react to the changes - if at all. Also observe how the gray squirrels react to other wildlife in the garden. Record whether the numbers of gray squirrels decline as a result of an increase in other wildlife visitors.
Select an area to study for a day to determine when gray squirrels are at their most active. The hours recorded for gray squirrel activity should be from 10 a.m. to 3 p.m. Create a daytime chart, and record how many different gray squirrels are seen each hour. Also make notes of whether the squirrels seem more energetic at different hours of the day. Determine whether the highest number of squirrels coincides with the animals being at their most energetic.