Why routing tables shows some routes which are not administratively configured in the system ?

Issue

• For an example in below output the routes like 10.126.X.0/24 , 169.254.X.0/24 are not administratively configured anywhere in the system, still it can be seen in routing table.

[EXAMPLE ~]$ netstat -nr
Kernel IP routing table
Destination     Gateway         Genmask         Flags   MSS Window  irtt Iface
10.126.P.0    0.0.0.0         255.255.255.0   U         0 0          0 eth0 
169.254.X.0    0.0.0.0         255.255.255.0   U         0 0          0 usb0
0.0.0.0         10.66.X.Y      0.0.0.0         UG        0 0          0 eth3

• IP on that system is;

[EXAMPLE ~] $ ifconfig 
eth0      Link encap:Ethernet  HWaddr E4:1F:xx:xx:xx:xx  
          inet addr:10.126.P.Q  Bcast:10.126.X.X  Mask:255.255.255.0
          inet6 addr: fe80::xxxx:xxxx:xxxx:xxxx/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

eth3      Link encap:Ethernet  HWaddr 00:15:xx:xx:xx:xx
          inet addr:10.66.X.Y  Bcast:10.66.x.x  Mask:255.255.255.0
          inet6 addr: fe80::215:17ff:feae:efd7/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1