You can track who you loan cat traps to in Shelterluv a couple different ways:
Using attributes
If you create a custom people attribute (How do I use attributes on people records?) called something like "Borrowing a Cat Trap," you would be able to easily add this attribute and quickly remove it from the attributes tab in each person's record.
You would also be able to filter for people with the attribute from the people tab on the main page to see who has a cat trap. 
Using memos
You can also use a custom memo type (which would not sortable from the main people page) to indicate more details about the trap that has been loaned out, such as the trap number(s) or the type of trap.
You can run a report based on memo type to identify those who have a trap. That report can be saved for future use and also used as an automated report.
Using activities
On the Field and Community Services side of Shelterluv, you can create a general Case titled something like “Cat trap loans,” which you will use as your “folder” for the loans. You can make the type / subtype = “Assist / Assist Public.”
Then, create an activity for each time a trap is loaned out, associating each to the main case.
The types / subtypes of the activities will be “Community Cat Program / Trap Rental.”
Set the “Due date” of each activity to be the day the trap is due back to your organization. Once the trap is returned, close the activity.
We recommend creating a standard format for titling the activities (eg. “Trap Rental — {name}”) to make sorting and searching especially easy.
From the main screen of the Field Services dashboard, you will be able to filter by subtype in order to be able to easily see all of your trap rental activities at once.
