1: Humans' loud voices can startle dogs and make them uncomfortable.

2: Dogs may find aggressive behavior, like rough petting, threatening.

3: Some dogs dislike direct eye contact from humans.

4: Dogs may get anxious around humans who move erratically.

5: Dogs may not like humans invading their personal space.

6: Dogs may be scared of humans wearing hats or sunglasses.

7: Dogs may dislike humans who smell strongly of unfamiliar scents.

8: Dogs may become aggressive when humans ignore their warning signs.

9: Some dogs may dislike interactions with overly emotional humans.