4 The Natural History of British Ducks 
Like other surface-feeding ducks, the Mallard is most alive and active at 
night. It is his chief feeding time, and then he and the Teal, more commonly 
than any other species, betake themselves to the muddy edge of a tide or 
pond well known to them as a storehouse of good things. Plunging their 
bills into the ooze as they paddle or float about, and filtering everything 
through the fringe of saw-like teeth with which their mandibles are lined, 
their marvellous delicacy of touch enables them to distinguish between nutri- 
tious and noxious matter, and so they get what they want for their daily meal. 
As showing the remarkable instinct — not to say reasoning powers — of 
the Mallard, I may mention that they are the only ducks which seem to have 
discovered the art of enticing worms and insects from the mud by standing 
up and * treading' any shallow water that may be above it, in much the same 
way as the Plovers and larger gulls * tread ' the land or the sand, for a similar 
purpose. Balancing themselves on their tails, they work their feet rapidly up 
and down until the mud below is thoroughly churned up ; the worms then come 
up to find out what is going on, and are promptly swallowed for their pains. 
A similar trick is known to the Lapwing and the Herring Gull, who — the 
one on ploughed land and the other on the sea-shore — occasionally practise 
it in the spring, pattering up and down with their feet on the wet ground; 
but I have never seen any duck but the Mallard make use of this ingenious 
ruse. The Shoveler and the Garganey, however, have an equally clever trick, 
which I shall describe later on. 
In winter, even as early as November, one may see on fine days a large 
flock of wild duck in which the majority of the birds are already paired off, 
but whether the pairing ofi" at this season means anything more than a mutual 
regard for each other's society, I cannot say. 
This is an interesting point in the habits of the Mallard, as one does not 
find quite the same thing in any other species ; and did we not know the 
somewhat indiscriminate nature of their attentions in the spring-time, it might 
be supposed that two birds paired for life, or, at any rate, for some years, like 
the crows and eagles. 
