What cultural faux pas should I try to avoid making in Pennsylvania?

We asked people in Pennsylvania if they could share any humorous cultural blunders they commited. For new expats, keep in mind that these incidents are an inevitable part of expat life. Learning to laugh about them is the key!...

Other Questions:

•  What do I need to know before retiring in Pennsylvania?
•  How do I meet people in Pennsylvania?
•  What is life like in Pennsylvania?
•  Is there a lot of crime in Pennsylvania?
•  Is there a lot of diversity? Are people in Pennsylvania accepting of differences?
•  What are the schools in Pennsylvania like?
•  Is the cost of living in Pennsylvania high?
•  What advice do you have for expats having a baby in Pennsylvania?
•  What are healthcare services like in Pennsylvania?
•  Is the cost of living in Pennsylvania high?
•  What type of recreational facilities are in Pennsylvania?
•  What is the weather like in Pennsylvania?
•  Are there good restaurants in Pennsylvania?
•  Where will I buy groceries and do other shopping in Pennsylvania?
•  What are the visa & residency requirements in Pennsylvania?
•  Are healthcare and health insurance expensive in Pennsylvania?
•  What do I need to know when buying property in Pennsylvania?
•  Are foreigners allowed to own property in Pennsylvania?
•  What appliances are typically included in a rental?