Doorbell avoidance techniques

1. A computer-implemented method comprising:

determining that a visitor arrived at a premises;

determining that the visitor used a computing device at a first time;

determining that a user device of a person of the premises received a message at a second time;

determining that a time period between the first time that the visitor used the computing device and the second time that the user device received the message satisfies a timing criteria; and

in response to determining that the time period satisfies the timing criteria, sending, to the user device, a notification that indicates that the visitor arrived at the premises.

2. The method of claim 1 , wherein determining that the time period satisfies the timing criteria comprises determining that the first time and the second time are at most a threshold time apart.

3. The method of claim 1 , wherein determining that the visitor used the computing device at the first time comprises:

analyzing, using object recognition, an image that depicts the visitor at the first time; and

determining that the image depicts the visitor holding the computing device.

4. The method of claim 1 , wherein determining that the visitor used the computing device at the first time comprises:

analyzing an audio signal that encodes sound captured during at least the first time; and

determining, using speech recognition, that the audio signal encodes a predetermined phrase.

5. The method of claim 1 , comprising:

determining that a second visitor arrived at the premises;

determining that the second visitor used a second computing device at a third time;

determining that a type of the second computing device is not a predetermined type; and

in response to determining that the type of the second computing device is not the predetermined type, determining to skip sending, to a second user device of a second person of the premises, a second notification that indicates that the visitor has arrived at the premises.

6. The method of claim 1 , comprising:

determining that a second visitor arrived at the premises;

determining that the second visitor did not use a second computing device within a threshold period of time of arriving at the premises; and

in response to determining that the second visitor did not use the second computing device within the threshold period of time of arriving at the premises, determining to skip sending, to a second user device of a second person of the premises, a second notification that indicates that the visitor has arrived at the premises.

7. The method of claim 6 , wherein the user device is the same user device as the second user device.

8. The method of claim 1 , comprising:

determining that a second visitor arrived at the premises;

determining that the second visitor used a second computing device at a third time;

determining that a second user device of a second person of the premises received a second message at a fourth time;

determining that a second time period between the third time and the fourth time does not satisfy the timing criteria; and

in response to determining that the second time period does not satisfy the timing criteria, determining to skip sending, to the second user device, a second notification that indicates that the visitor has arrived at the premises.

9. The method of claim 8 , wherein the second user device is a different user device than the user device.

10. A system comprising one or more computers and one or more storage devices on which are stored instructions that are operable, when executed by the one or more computers, to cause the one or more computers to perform operations comprising:

determining that a visitor arrived at a premises;

determining that the visitor used a computing device at a first time;

determining that a user device of a person of the premises received a message at a second time;

determining that a time period between the first time that the visitor used the computing device and the second time that the user device received the message satisfies a timing criteria; and

in response to determining that the time period satisfies the timing criteria, sending, to the user device, a notification that indicates that the visitor arrived at the premises.

11. The system of claim 10 , wherein determining that the time period satisfies the timing criteria comprises determining that the first time and the second time are at most a threshold time apart.

12. The system of claim 10 , wherein determining that the visitor used the computing device at the first time comprises:

analyzing, using object recognition, an image that depicts the visitor at the first time; and

determining that the image depicts the visitor holding the computing device.

13. The system of claim 10 , wherein determining that the visitor used the computing device at the first time comprises:

analyzing an audio signal that encodes sound captured during at least the first time; and

determining, using speech recognition, that the audio signal encodes a predetermined phrase.

14. The system of claim 10 , the operations comprising:

determining that a second visitor arrived at the premises;

determining that the second visitor used a second computing device at a third time;

determining that a type of the second computing device is not a predetermined type; and

in response to determining that the type of the second computing device is not the predetermined type, determining to skip sending, to a second user device of a second person of the premises, a second notification that indicates that the visitor has arrived at the premises.

15. The system of claim 10 , the operations comprising:

determining that a second visitor arrived at the premises;

determining that the second visitor did not use a second computing device within a threshold period of time of arriving at the premises; and

in response to determining that the second visitor did not use the second computing device within the threshold period of time of arriving at the premises, determining to skip sending, to a second user device of a second person of the premises, a second notification that indicates that the visitor has arrived at the premises.

16. The system of claim 15 , wherein the user device is the same user device as the second user device.

17. The system of claim 10 , the operations comprising:

determining that a second visitor arrived at the premises;

determining that the second visitor used a second computing device at a third time;

determining that a second user device of a second person of the premises received a second message at a fourth time;

determining that a second time period between the third time and the fourth time does not satisfy the timing criteria; and

in response to determining that the second time period does not satisfy the timing criteria, determining to skip sending, to the second user device, a second notification that indicates that the visitor has arrived at the premises.

18. The system of claim 17 , wherein the second user device is a different user device than the user device.

19. A non-transitory computer-readable storage medium encoded with instructions that, when executed by one or more computers, cause the one or more computers to perform operations comprising:

determining that a visitor arrived at a premises;

determining that the visitor used a computing device at a first time;

determining that a user device of a person of the premises received a message at a second time;

determining that a time period between the first time that the visitor used the computing device and the second time that the user device received the message satisfies a timing criteria; and

in response to determining that the time period satisfies the timing criteria, sending, to the user device, a notification that indicates that the visitor arrived at the premises.

20. The non-transitory computer-readable storage medium of claim 19 , wherein determining that the time period satisfies the timing criteria comprises determining that the first time and the second time are at most a threshold time apart.