You ask it as though you are not the person giving them permission to stay:
As the Buyer you have Insurance, starting from the day that the Escrow Closes.
And you have the right to your house.
If they are squatting, you might want to serve them and their Agent with a NOTICE.
The owner of record is responsible for any damages or injuries incurred on the property at the time of the incident. So if Seller is allowed to occupy the property after settlement then then the new buyer would be liable and you would want to make sure home owners insurance policy would cover anything that occurred.
John R. Thomas
Primary Residential Mortgage
Technically, once title has passed, the new owner would be liable from there forward, however, lawyers should be be involved from that point , with a detailed contract, clearly outlining terms and conditions, of the extended stay.
Faith C Borbee
Licensed Realtor, DE
Remax Associates, Wilmington