The phrase "are careless" can be replaced with a variety of synonyms to convey a similar meaning. For instance, one could say "are inattentive" or "are negligent" to describe individuals who are not paying enough attention. Another alternative is "are heedless" which connotes a lack of consideration or regard for consequences. Similarly, "are thoughtless" implies a disregard for the effects of one's actions on others, while "are reckless" suggests indifference to potential harm or danger. Other possible synonyms for "are careless" include "are lax", "are irresponsible" and "are indifferent". In each case, the implication is that the individuals in question are not taking the necessary care and attention in whatever they are doing.