Did you know that penguins expel all of the seawater they swallow while hunting for food in the ocean by sneezing? Also, here are this week's subway changes:

South Ferry-bound 1 trains will run express from 72 St to Times Sq-42 St from 11:45 p.m. Friday to 5 a.m. Monday.

Flatbush Av-Brooklyn College bound 2 trains run express from 72 St to Times Sq-42 St from 11:45 p.m. Friday to 6:30 a.m. Sunday, and again from 11:45 p.m. Sunday to 5 a.m. Monday.

3 trains will operate to/from New Lots Av, replacing the 4 in Brooklyn, from 11:45 p.m. Friday to 5 a.m. Monday.

4 trains will not run between New Lots Av/Utica Av and Brooklyn Bridge-City Hall in either direction, with that change in effect from 11:45 p.m. Friday to 5 a.m. Monday. All trains will run local between 125 St and Brooklyn Bridge-City Hall during that time. Woodlawn-bound trains will run express from 149 St-Grand Concourse to Burnside Av from 3:45 a.m. Saturday to 10 p.m. Sunday.

5 trains will not run between Eastchester-Dyre Av and E 180 St in either direction from 11:45 p.m. Friday to 5 a.m. Monday. Trains will not run at all between Bowling Green and Grand Central-42 St from 6 a.m. to 11 p.m. Saturday and from 8 a.m. to 11 p.m. on Sunday.

Main St-bound 7 trains will run express from Queensboro Plaza to 74 St-Broadway from 3:45 a.m. Saturday to 10 p.m. Sunday.

D trains will reroute in Manhattan and Brooklyn from 10:30 p.m. Friday to 5 a.m. Monday. The schedule is as follows: D trains will operate between Norwood-205 St and 59 St-Columbus Circle, then reroute via the A to/from Jay St-MetroTech, and then via the F to/from Stillwell Av, with trains running express in Manhattan.

Jamaica Center Parsons/Archer-bound E trains will run express from Queens Plaza to Forest Hills-71 Av from 11:45 p.m. Friday to 6:30 a.m. Sunday, and again from 11:45 p.m. Sunday to 5 a.m. Monday. Trains on that track with skip 75 Av and Briarwood from 11:45 p.m. Friday to 5 a.m. Monday.

Jamaica-179 St bound F trains will skip 75 Av, Briarwood, and Sutphin Blvd from 11:45 p.m. Friday to 5 a.m. Monday. Trains will reroute in Manhattan and Brooklyn from 10:30 p.m. Friday to 5 a.m. Monday. The changes are as follows: F service will operate between Jamaica-179 St and Lexington Av/63 St, then reroute along the Q to/from Atlantic Av-Barclays Ctr, and then via the D to/from Coney Island-Stillwell Av. Trains will run express in Manhattan and skip DeKalb Av on days and in evenings.

M trains will operate to/from the Chambers St J station from 10:30 p.m. Friday to 5 a.m. Monday. Trains will run along the J line in Manhattan after Essex Street.

All N trains will run local in Brooklyn between 59 St and Atlantic Av-Barclays Ctr from 10:30 p.m. Friday to 5 a.m. Monday. Trains will reroute along the R line in both directions between DeKalb Av and Canal St during this time, stopping at Jay St-MetroTech, Court St, Whitehall St, Rector St, Cortlandt St, and City Hall.

Forest Hills-71 Av bound R trains will run express from Queens Plaza to 71 Av rom 6:30 a.m. to midnight on Saturday and Sunday.