From USPS: The U.S. Postal Service is advising all mailers shipping Lives (birds, insects, etc.) nationwide, the current embargo of Lives is being extended another 24 hours through Sunday night February 1.
This impacts all Lives regardless of air or ground transportation. Temperatures are starting to rise above freezing in various parts of the country, but weather impacts remain. Air network impacts are extensive. Surface transportation has been impacted due to snow and ice accumulation on the roads from Texas to the Northeast.
Due to the extension, acceptance of Lives will resume on Monday February 2, and transportation will resume that evening based on revised conditions.