Can you solve this Anglo-Saxon riddle
Ic wiht geseah in wera burgum,
seo þæt feoh fedeð. Hafað fela toþa;
nebb biþ hyre æt nytte, niþerweard gongeð,
hiþeð holdlice ond to ham tyhð,
wæþeð geond weallas, wyrte seceð;
aa heo þa findeð, þa þe fæt ne biþ;
læeð hio þa wlitigan, wyrtum fæste,
stille stondan on staþolwonger,
beorhte blican, blowan ond growan.
I saw a strange thing in men's strongholds
feeding cattle. Crammed with teeth,
it's useful beak is bent down;
it roams through plots, seeking plants,
raids them swiftly and returns home;
it always ferrets out the frail,
leaves the fine ones firmly rooted
standing still on their stalks
brightly blooming, glowing and growing.