Day old chicks need NOTHING for 72 hours. Juveniles over 4 weeks old can live for days on the moisture in ripe tomatoes, and the tomatoes won't hurt them. I have NEVER had a postal service employee look in a sealed box. I use only Horizon boxes so that nothing can be stacked on top of them. That's especially important in warm weather.Don't even think about shipping in HOT weather, or on any day but Monday or Tuesday. Better safe than sorry.
From USPS website
526.3 Live, Day–Old Poultry
526.31 General
The following live, day–old animals are acceptable for mailing when properly packaged: chickens, ducks, emus, geese, guinea fowl, partridges, pheasants (only during April through August), quail, and turkeys. All other types of live, day–old poultry are nonmailable. Day–old poultry vaccinated with Newcastle disease (live virus) also is nonmailable.
526.32 Mailability Requirements
The specific types of day–old poultry named in 526.31 and DMM 601.9.3.2 are mailable subject to the following requirements:
Poultry that is not more than 24 hours old and is presented for mailing in the original, unopened hatchery box from the hatchery of origin. Date and hour of hatching is noted on the box. Box is properly ventilated, of proper construction and strength to bear safe transport in the mail, and is not stacked more than 10 units high. Day–old poultry is mailed early enough in the week to avoid receipt at the office of address (in case of missed connections) on a Sunday, a national holiday, or the afternoon before a Sunday or national holiday. Day–old poultry can be delivered to the addressee within 72 hours of the time of hatching. If day–old poultry is sent at a Parcel Post rate, special handling postage must also be paid. If day–old poultry is sent via air transportation (i.e., Express Mail, Priority Mail, or First–Class Mail), all provisions of the airlines must be met. Delivery of the mailpiece is dependent on the availability of air carriers having available equipment to safely deliver the day–old poultry within the specified time limit. Boxes of day–old poultry of about identical size, securely fastened together to prevent separation in transit, may be accepted for mailing as a single parcel, provided the total length and girth combined does not exceed Postal Service limits.
526.4 Adult Fowl
526.41 General
Disease-free adult fowl may be mailed domestically when shipped under applicable law in accordance with DMM 601.1.7. Adult chickens, turkeys, guinea fowl, doves, pigeons, pheasants, partridges, quail, ducks, geese, and swans are mailable when properly packaged. Adult fowl must be packaged without food or water because liquids, moisture, and loose foodstuffs can cause damage to the shipping container, other mail, and Postal Service equipment during transport.
So, how are you guys getting around this? I wouldn't want to ship any of my chicken babies or adults without SOMETHING!!!! How do they get to the water MooMooDiddy? Do you have holes in it and wouldn't it spill? Sorry guys, I just can't figure out how to do this properly, I can see putting in fruit or veggies but it seems like they would bounce and slam around and possible conk the chicks or chickens and hurt them.