Many dog owners are familiar with the so-called guilty behavior of their dogs when they have done something that they are not allowed to do. Cats have some of this too, although they typically have to be caught in the act and their behavior is to run away when they hear you coming, rather than looking submissive with their tails between their legs. Dogs and cats may act contrary to their training and sometimes seem to know it when they do.

You might be interested in the work of Frans de Waal and his students and colleagues. An easy introduction is his book "Good Natured", though much more systematic research has also been carried out since.

And how about looking at preverbal infants? There is an explosion of interest in moral "judgments" of infants. Paul Bloom has written a book on this research, much of it carried out by him and his colleagues. (I can send you a brief review of some of this literature.)

My view is that social species whose individuals are interdependent must evolve some means of social control, which at its most basic requires some degree of concern for others' welfare, some degree of self control, and probably some degree of motivation to punish harmdoers. This is nothing like the "ethics" mentioned by Wilhelm Kuntner above, but it does fit the social behavior of some social animals and preverbal children.

You might find Steven Pinker's "The Stuff of Thought" interesting on the subject of what can be thought without language.

In my mind, the answer to your question depends on the definition of morality that you have. In his Tanner lecture, Franz de Waal shows the bottom-up morality (e.g. a capacity for empathy, a tendency for reciprocity, a sense of fairness). However, in his response to commentators (e.g. Christine M. Korsgaard, Peter Singer), he clarified his theory, and stresses that human morality can be divided into three distinct levels: moral sentiments and social pressure (both do exist in other primates), and judgment and internalization (here the similarities between human and other primates end). What is morality then?

Please go to this link :

https://www.babbel.com/en/magazine/can-language-affect-morality

Bertrand Russell, 1923, Human Knowledge : Its Scope and Limits , George Allen and Unwin Ltd.

At page 53:

Language serves not only to express thoughts, but to make possible thoughts which could not exist without it. It is sometimes maintained that there can be no thought without language, but to this view I cannot assent: I hold that there can be thought, and even true and false belief, without language. But however that may be, it cannot be denied that all fairly elaborate thoughts require words.