In Ubuntu Desktop my Arduino Uno shows up as /dev/ttyACM0 .... where is it in android?

When I connect an Arduino Uno via USB to my Linux Ubuntu Desktop 14.04, the arduino shows up as /dev/ttyACM0 .... When I connect it via usb to an android phone the device is powered and recognized in Android apps, but I can't seem to find it when i look in a terminal emulator at the /dev folder. When I browse android's directory structure using terminal, where can I find the analogous device? Further elaboration: On the desktop I can access the USB arduino device with no trouble, using screen /dev/ttyACM0 or I can even pipe characters to it directly such as: echo -n w > /dev/ttyACM0 On the android device, there are no tty* devices in that folder at all. Someone I know recommended I install a full linux distro on top of android, GNUroot Debian, and maybe it would be there. I did this on both an LG Nexus 5 with android 6.0 as well as a Moto Droid 4 with Android 4.1.2, in hopes that those familiar devices /dev/ttyACM would show up, but they didn't. Is there any similiar thing to /dev/ttyACM0 in android? Thank you! android-controlled-robot