Besides getting some free grub, grumbling is not in the senior's nature, anyway.
From the sltrib.com
In July 1996, grumbling that the CSO was not giving it a fair deal, Argyle quit.
From the economist.com
He retained the post on and off, in spite of much grumbling, for about 35 years.
From the en.wikipedia.org
On the contrary, I was busy skipping church and grumbling about my wet sneakers.
From the ocregister.com
There was also no lack of grumbling about the rigors of fasting among the laity.
From the en.wikipedia.org
In fact, grumbling about having to buy insurance is non-existent in Switzerland.
From the nation.time.com
The grumbling about his performance remains, even among his closest colleagues.
From the independent.co.uk
That made Rose fans happy, though some are still grumbling about the changover.
From the ocregister.com
Much of the fan grumbling about the program fixates on the team's talent level.
From the washingtontimes.com
More examples
Rumble: a loud low dull continuous noise; "they heard the rumbling of thunder"
Grouch: show one's unhappiness or critical attitude; "He scolded about anything that he thought was wrong"; "We grumbled about the increased work load"
A complaint uttered in a low and indistinct tone
Murmur: make complaining remarks or noises under one's breath; "she grumbles when she feels overworked"
To utter or emit low dull rumbling sounds; "he grumbled a rude response"; "Stones grumbled down the cliff"
The S-300 is a series of Russian long range surface-to-air missile systems produced by NPO Almaz, all based on the initial S-300P version. The S-300 system was developed to defend against aircraft and cruise missiles for the Soviet Air Defence Forces. ...
A low thundering, rumbling or growling sound; The sound made by a hungry stomach; A complaint; To make a low, growling or rumbling noise, like a hungry stomach or certain animals; To complain; To utter in a grumbling fashion
(grumbled) the past tense of "grumble", which means to complain sadly.