linux mv 类型过滤

我想把文件移入文件夹里面。

[huangxinzhen@localhost cxx]$ find . -type f -exec mv {} t1 \;
mv: `./t1/test' and `t1/test' are the same file
[huangxinzhen@localhost cxx]$ find . -type f -exec mv {} t1/ \;
mv: `./t1/test' and `t1/test' are the same file
mv: `./t1/Makefile' and `t1/Makefile' are the same file
mv: `./t1/main.c~' and `t1/main.c~' are the same file
mv: `./t1/main.o' and `t1/main.o' are the same file
mv: `./t1/main.c' and `t1/main.c' are the same file
mv: `./t1/tags' and `t1/tags' are the same file
mv: `./t1/Makefile~' and `t1/Makefile~' are the same file
mv: `./t1/Session.vim' and `t1/Session.vim' are the same file
[huangxinzhen@localhost cxx]$ ll t1
total 48
-rw-------. 1 huangxinzhen huangxinzhen 5009 Mar  8 23:23 main.c
-rw-------. 1 huangxinzhen huangxinzhen 5004 Mar  8 23:22 main.c~
-rw-rw-r--. 1 huangxinzhen huangxinzhen 4172 Mar  8 23:23 main.o
-rw-r--r--. 1 huangxinzhen huangxinzhen  152 Mar  8 23:20 Makefile
-rw-r--r--. 1 huangxinzhen huangxinzhen  149 Mar  8 23:18 Makefile~
-rw-rw-r--. 1 huangxinzhen huangxinzhen 4022 Mar  8 23:24 Session.vim
-rw-r--r--. 1 huangxinzhen huangxinzhen  646 Jul 13  2013 tags
-rwxrwxr-x. 1 huangxinzhen huangxinzhen 7484 Mar  8 23:23 test
[huangxinzhen@localhost cxx]$ ll

移动虽然成功了，可就是出现are the same file，不知道是怎么回事。